ADHD is widely recognized to be a frontal-subcortical circuit disorder, with the affected brain regions as possible contributors to both cognitive as well as behavioral symptoms. Frontal-subcortical circuit disorders most often lead to attention impairments, which implicates that differential diagnosis only based on behavioral criteria can be very difficult.

Cognitive and neuropsychological functions

The main area involved in ADHD is the prefrontal cortex and its associated structures, which are responsible for executive functions such as planning, problem solving and evaluating. Also, structures responsible for transferring information from one hemisphere to the other, like the corpus callosum, are found to be affected in children with ADHD. Also, research has shown that cerebellar regions like the right prefrontal are reduced in volume. This suggests that ADHD not only affects the frontal lobes, but a number of interrelated midline circuits and tracts extending from the subcortical cerebellar to the cortical prefrontal regions. This axis is likely the seat of most known psychopathologies, like ADHD. Therefore, symptoms like impulsivity, hyperactivity and inattention are probably just one facet of the disorder, with multiple other systems and area’s likely to be affected.

Impulsivity due to an impaired inhibitory control system results in maladaptive externalizing behaviors like fearlessness and carelessness. This should be regulated by the frontal lobes, like in typically developing children. Executive attention as well as behavioral regulation highly depends on inhibitory functions. Therefore, the theory of ADHD by Barkley states that deficits in multiple cortical and subcortical regions can be found in children with poor inhibitory control. A distinction can be made between top-down cortical inhibitory problem considering interference control and behavioral inhibition, and bottom-up subcortical problems which are related to (the lack of) response to reinforcement and punishment. It seems that the right prefrontal cortex is more involved in representation and maintenance of adaptive responding and suppressing irrelevant events, while the basal ganglia is more involved in suppression of response. All in all, inhibitory functions consist of multiple implicated areas.

It seems that children with ADHD not so much have a primary attention deficit, but experience difficulty with the executive control of attention. This can be explained by the specific abnormalities linked with attention dysfunction, which are also involved in the inhibitory process. The deficits in these brain area’s result in a disorder of attention control . Since dysfunctions in the frontal brain areas can be associated with multiple disorders, heterogeneity among children referred for attention problems must be considered.

A defect in the regulation of dopamine can lead to dysfunctional frontal-subcortical circuits, resulting in hyperactive behavior. Also, children with ADHD often experience impaired motor precision and consistency, which frequently results in comorbid Developmental Coordination Disorder. Since individuals with ADHD show impairments in both areas, it’s important to determine whether a motor deficit is the result of a cortical motor (e.g. basal ganglia), subcortical cerebellar problem or both. Furthermore, children with ADHD have more sensory processing deficits than controls. This could be due to impaired thalamatic functioning in individuals with ADHD or poor efficiency of connectivity of white matter connections between the anterior and posterior regions. Also, problems with transferring information because of a deficit in the corpus callosum like mentioned earlier could lead to problems with sensory-motor integration.

Executive functioning

Although deficits in executive functioning is probably the most consistent neuropsychological finding among children with ADHD, there is also still some controversy. We consider ADHD as best characterized by executive deficits in vigilance, response inhibition, planning and working memory. It’s important to mention that these impairments couldn’t be explained by intelligence, comorbidities or achievements. Because of its similarities with executive function, fluid reasoning can be considered as a cognitive test. Both require the abilitiy to solve novel problems, benefit from feedback and adaptive responding. As the complexity of problem solving increases, so does dorsolateral prefrontal functioning. Children with ADHD and social problems show impairments in their fluid reasoning and visual organization/praxis measures with high executive demands. This suggests that fluid reasoning is in part a measure of right dorsolateral prefrontal functioning, in which individuals with ADHD show deficits. A strong predictor of fluid abilities is working memory, which is also often impaired in individuals with ADHD. Especially spatial working memory appears to be impaired. Executive functions that include working memory have been found to be related to hyperactive-impulsive symptoms.

Children with ADHD exhibit deficits in processing speed and efficiency, possibly resulting from a lack of energy supply to rapidly firing neurons. This appears to be specific for the inattentive ADHD subtype. Because of all those deficits discussed, and its impact on encoding, storing, and retrieving information, it’s not surprising that children with ADHD often experience learning difficulties. Academic deficits have long been considered the final common pathway for children with ADHD. Specific Learning Disabilities (SLD) therefore is an often found comorbid disorder. Difficulties with attending to the novel information presented is what makes new learning especially hard for children with ADHD. Long-term memory storage on the other hand doesn't seem to be impaired. The difficulty with new information may be due to a working-memory overload because of the inability to filter out irrelevant information. Researchers found meaning to facilitate learning. When children ought something important, they more easily remember it. Therefore emotional salience increases episodic memory in children with ADHD. They also found that nucleus accumbens deficiencies may lead to deficient motivation or reinforcement during new learning situations.

Since the frontally mediated executive functions govern all other aspects of cognition, it’s not surprising that children with ADHD also experience visual-spatial-holistic right hemisphere and auditory-verbal-crystallized left hemisphere dysfunctions. These impairments can also influence the ability to process information. Especially visual working memory seems to be impaired, but luckily this can be improved with medication treatment. The problems with visual-spatial-holistic processing may be due to its strong relationship with executive function, which is often impaired in children with ADHD. Furthermore, attention deficits overlap with auditory processing and language disorders, which can interfere with the learning, behavioral and social outcomes of affected children. Poor internalization of language in ADHD is in part responsible for poor behavior regulation and impulse control. Children who do not process language efficiently will appear inattentive in the classroom, and could be diagnosed with comorbid ADHD. But do those children really have ADHD? Early research did not screen for comorbid SLD, but auditory processing and language deficits are more often associated with SLD than ADHD. It could be that language deficits in ADHD are more related to the executive and expressive aspects of language.

Comorbidities

Children with ADHD often show impulsive, aggressive and noncompliant behavior which results in conflicts with their peers and family. They show impaired emotional and behavioral inhibition. These behaviors most often occur with children who have comorbid disorders like Conduct Disorder(CD) or Oppositional Defiant Disorder (ODD). The latter is the most common comorbid condition, with an occurrence of 40 to 60% of children with ADHD, mostly males.

Impaired executive functioning can result in low self-esteem, poor concentration and irritability. Therefore, children with ADHD may develop a depression. Rates of comorbidity range from 10 to 50%, and children with the inattentive type of ADHD are more likely to develop an internalizing disorder. Another highly common comorbid disorder is Bipolar Disorder (BPD) . This comorbidity increases the risk of neurocognitive deficits and poor treatment response because mania are often mistaken for ADHD in children, but require a different form of medication.

Anxiety disorders can be primarily linked to children who suffer from the inattentive subtype of ADHD. A more severe form of anxiety is Obsessive-Compulsive Disorder which also shows similarities with ADHD and therefore is a comorbid disorder. Many children with Tourette Syndrome also suffer from ADHD. This is probably because the involuntary tics wax and wane, with attentional problems found to precede or follow the onset of tics.

Function measures

Some executive function measures are more effective than others in the diagnosis of ADHD and for conducting school neuropsychological evaluations. Most tests measure response inhibition, interference control, working memory vigilance and planning, but are generally more sensitive to ADHD than they are specific. This is probably due to the fact that several other disorders also show impaired performance on these and other executive measures. School neuropsychologists should use a variety of direct assessment tools for ADHD diagnosis and intervention purposes, because no single assessment tool is sufficient enough. Indirect measures of ADHD symptoms, such as objective behavior rating scales are also important for a comprehensive ADHD evaluation, but not sufficient for a differential diagnosis of ADHD.

Because comorbidity is more the rule than the exception among psychiatric disorders including ADHD, interrelationships can only be clarified by examination of underlying deficits. It’s possible that children who meet behavioral criteria for ADHD actually suffer from their comorbid disorder as the primary disorder, with secondary attentional problems. Therefore it’s important to determine to what extent psychiatric disorders have similar or different etiologies, if these differences can lead to more accurate diagnostic techniques and whether these differences can lead to more effective treatment practices and outcomes.

Although research into these matters provide sometimes conflicting findings, the overall conclusion is that most (if not all) psychopathologies have a basis in the frontal-subcortical circuits, and that their dysfunctions lead to observable behavior and learning problems. There are at least five interdependent frontal-subcortical circuits with dozens of related executive functions. Therefore impairments in this area can lead to many different psychiatric disorders. So far there is no clear explanation for all these differences, but different gene environments are suggested as one of the reasons. Another important issue is how we define disorders. Because behavioral diagnostic methods lead to heterogeneous samples of children diagnosed with psychiatric disorders, this is often more meaningful for diagnosis than neuropsychological measures. However, to explain differences within the group of children with a certain disorder, neuropsychological assessment can be very useful. More information about differences within a disorder can lead to more targeted treatment plans and interventions, because those are currently quite ‘global’.

The simultaneous processing of motor and cognitive demands is necessary for the production of written text. Children develop automaticity in their handwriting while learning to write, such that motor demands of writing doesn’t interfere with higher-order cognitive processes related to composition. When this automaticity isn’t present, the flow and planning of ideas and their translation into written form may be disrupted, which affects the complexity of the text.

Furthermore, the quality of handwriting is significantly correlated with the level of academic achievement during school years, and is a predictor of more general learning difficulties later in life. The World Health Organization (WHO) therefore identifies the skill of writing as part of the Activities and Participation Domain of health. Poor handwriting can also affect the perception of a child’s abilities, self-esteem, personal relationships and psychosocial well-being.

Children with neurodevelopment disorders such as ADHD, DCD and ASD often experience handwriting difficulties. Autism Spectrum Disorder concerns neurodevelopmental disorders characterized by symptoms such as presence of restrictive, repetitive and stereotypical behaviors, activities and interests plus impairments in communication and social interaction. ASD is also often associated with fine motor difficulties and executive function impairments which are necessary for the performance of skilled motor task. This explains why ASD in children is often related with handwriting difficulties.

Determinants of handwriting function

Learning and acquisition of handwriting is a function of the interaction between the child, the writing task and the environment. The Sequential Handwriting Process argues that the handwriting process starts with the presentation of the text to be written. This can be a visual, audial or self-intended presentation. Second, a series of cognitive steps have to be taken to retrieve the motor program for the appropriate letter allograph. This translates into specific control instructions for muscle groups concerning the size and speed of the required movement. Appropriate force on the pen and paper, movements within strict spatial limits and the use of the correct velocity are all necessary factors for fluid handwriting. Sensory perceptual feedback provides information for error correction.

Fine motor skills enable fluent manipulation of the writing and thereby producing letters with the desired specific form, size and position on the writing surface. The quality of handwriting therefor logically correlates with aspects of fine motor control. Deficits to the fine motor skills often occur in children with ASD, especially in children with Asperger’s syndrome. Proper timing and force control of the arm, hand and finger movements derive from fine motor skills, and are all necessary to produce accurately formed letters. Children with ASD also regularly experience difficulties with planning, executing and organizing movements or suffer from dyspraxia which both affect coordination, fluency and speed of motor activities. Since movement planning is necessary to produce handwriting, these impairments also cause problems producing written text. They therefore develop a certain slowness in their movement preparation and reaction times. Muscle tone, muscle stress and tension and pencil grip are also important factors in producing handwriting but are often impaired in individuals suffering from ASD.

Another integral part of proficient handwriting, specifically in the planning and execution of the written product, are visual perception skills. Not only do those skills allows to discriminate between letter forms, they also provide information for error monitoring. Interestingly, since handwriting movements are highly pre-structured and organized, the reliance on vision generally diminishes as skilled handwriting develops. ASD is particularly associated with atypical patterns in visual processing, including differences in perception of motion, superior processing of fine details and atypical processing of global structure. Overall, ASD is not associated with global deficits in visual reasoning and discrimination, but the atypical patterns of visual perception in ASD might contribute to handwriting difficulties.

Visual-motor integration is the ability to integrate the visual images of letters or shapes with the appropriate motor response. This is typically assessed by examining the ability of children to copy geometric forms using pencil and paper. It is therefore considered as a degree of coordination between visual perception and hand-finger movements. The ability of visual-motor integration significantly correlates with the production of legible handwriting. So far, no strong evidence has been found that children with ADHD exhibit deficits in visual-motor integration. Sins visual-motor integration combines both motor abilities and visual perception, poor performances may result from impairments in one of these two domains or in the integration of the two domains.

The awareness of the movement and position of limbs in space as well as information regarding touch, pressure and pain are referred to as kinesthesia and proprioception. Kinesthesia provides feedback and a monitoring of extent and force or speed of movements for the purpose of error correction. The ability to improve performances over time could be hindered by deficits in kinesthetic perception. Currently there is no significant evidence suggesting deficits in kinesthesia and proprioception in children with ASD.

Studies on handwriting in individuals with ASD

Officially, the quality of handwriting is measured in terms of speed and legibility. Legibility refers to the recognizability of handwriting and includes factors such as sizing, alignment, letter form and spacing. Several studies have reported poor legibility in children with ASD, especially in the area of letter formation. The quality of letters is measured by letter form which considers factors such as shape reversals, distortions and rotations. Commonly found mistakes in the handwriting of children with ASD are sharp edges instead of smooth curves and larger letter extensions. Poor letter formation may be due to difficulties with fine motor skills and pencil manipulation.

Several researches show a lot of discordance with regard to alignment, spacing and sizing. Although deficits in all of these areas are expected considering the impairments in visual perception and visual motor integration, only one study has shown poorer performances than peers without ASD. The same accounts for speed. Interestingly though, increased consistency in letter formation was reported to be associated with a decrease in speed in children with ASD but not in typically developing peers.

Very few research has been conducted on the nature of handwriting difficulties in children with ASD. The most consistent finding is that legibility, especially letter formation, is impaired in children with ASD. This impairment positively correlates with deficits in motor skills. The great amount of disparity in several researches may be due to differences in the nature of the writing tasks used in the studies and the heterogeneity of the ability profiles in children with ASD. Also, the current studies have mainly focused on the final, static written product while writing is a dynamic process involving changes in direction, forces, velocities and accelerations. So far no research has been conducted on these process-related aspects.

Defining dyslexia

Nowadays, dyslexia is defined as a specific learning disability with a neurobiological origin. It causes difficulties with the accurate and fluent recognition of words, is characterized by poor spelling and impairs decoding abilities. This symptoms often result in a deficit in the phonological component of language, which is often unexpected in relation to other cognitive abilities. Therefore, dyslexia has also been called ‘the unexpected difficulty in reading’. This means that a child who possesses all factors necessary to be a good reader, such as intelligence and motivation, still struggles.

To measure dyslexia as a unexpected difficulty, IQ and reading achievement were compared to look for a discrepancy between those two. Unfortunately, this means that in real-life children often had to fail before they got diagnosed and received help. Therefore this was also called the wait-to-fail-model. Alternative approaches were needed. One such an approach focuses on a more dynamic assessment, which is also applicable to early grades and therefore early recognition. The ongoing development or fluency in component reading skills such as letter recognition is measured frequently and compared with expected norms. Another approach provides all children with a evidence-based reading instruction and frequently monitors their progress. Children who do not make any progress are selected to receive additional support. This is called the response to intervention.

Recent data has suggested that reading difficulties occur as part of a continuum that includes nonimpaired as well as disabled readers. This also includes dyslexia, which therefore seems to occur in degrees of severity. This dimensional model also suggests that cut of points may be implemented to define groups but only differentiate in degree, not kind. These arbitrary points thus may haven no biological validity. Given these findings, children who do not meet these arbitrary criteria may still require and profit from some help.

Epidemiology of dyslexia

Dyslexia is highly prevalent, though exact numbers depend on the definition and cut-off points established as criteria. There is a string misbelief that reading problems are outgrown or represent a developmental lag. It is important to address reading problems expressed early in life, otherwise they will persist with time. Furthermore, research shows a much better response to interventions provided in the first years of school compared with those presented in the later years of primary school.

A lot more boys than girls get diagnosed with dyslexia. This seems partially due to the often more disruptive behavior of boys in the classroom, which leads to earlier recognition through the traditional school identifications. Mostly, girls are more quit but they may struggle with reading on their own. The identification of dyslexia should not rely on behavioral difficulties. Using ‘response to intervention’ could prevent this.

Phonological awareness

The language system is a hierarchy of different modules, starting with the phonological module, which is dedicated to processing the fundamental units of language: phonemes. We consider language to be generative, since it can produce thousands of words out of just 44 phonemes (in the English language). The phonological module assembles the phonemes into words for the speakers, and disassembles the words into phonemes for the listener. Coarticulation is the term used to describe the process of different segments sounding seamless to the listener. The fact that spoken language doesn’t give any clue to its underlying segmental nature can be a challenge for the reader-to-be.

Spoken language is innate, whereas written language is acquired and must be taught. The literature suggests that the prime challenge for beginning readers is to link the letters to spoken language: the phonemes. Therefore this should serve as the major focus of early reading instruction.

The core of reading is the ability to identify, recognize and manipulate syllables and phonemes within spoken language. We refer to this as phonological awareness (PA), what also seems to be the core of reading difficulties. Reading acquisition can be predicted by PA, it differentiates good and poor readers and instructions with the intention to improve PA improve reading. Children first develop an awareness to words as a whole, followed by syllables and then phonemes: phonemic awareness. Research suggests that reading itself is necessary for developing PA, and emphasis the importance of reading instruction to the development of this critical skill.

Alphabetic orthographies use letters and clusters of letters in order to produce phonemes and words, where logographic orthographies use characters (like for example in China and Japan). Dyslexia occurs in both orthographies. Children learn to read words more accurately when the letter-sound mappings are very consistent, like in the Italian language where there’s a great predictability of sound-symbol linkages. Variations in consistency will influence the expression of dyslexia across different languages. In consistent orthographies it is relatively easy for good readers as well as dyslectics to learn reading words accurately. Therefore, dyslexia may only just be recognized until later on in school because only reading fluency is affected while reading accuracy is relatively intact. Spelling may be effected because dyslectics have trouble with inconsistencies between sound and spelling.

Etiology

Dyslexia appears to be inheritable, interestingly enough especially in in children with high IQ’s. Nowadays, half of the variance in dyslectics can be explained by genetic factors while the rest can be attributed to environmental factors. Taking this information into account, children from dyslectic parents or with dyslectic siblings should be considered at risk for developing dyslexia. Therefore they should be carefully observed for signs of reading difficulties. It’s important to emphasize that a genetic aetiology doesn’t mean that interventions do not work for this group of children. They can still benefit from evidence-based intervention and deserve this extra help.

By using neuroimaging technology, neuroscientists have been able to identify several interrelated neural networks of reading in the left hemisphere (for example Broca’s area). Functional brain imaging studies have shown deficits in the left hemispheres of disabled readers, explaining their reading difficulties. Nevertheless, they seem to have developed compensatory systems in both hemispheres. Several studies have shown that neural systems for reading can be improved and influenced by reading interventions. The way children are taught can foster the development of those automatic neural systems that serve skilled reading, so teaching matters. It is still necessary to determine the precise relationship between types of interventions, changes in brain activation and clinical improvements.

Studies using fMRI have indicated that dyslexics are not able to use sound-symbol linkages growing into adulthood, and start to rely on memorized words. By reading words from memorization, familiar words are recognized and easy to read but they show difficulties reading unfamiliar words. This is a problem because memory has limited capacity. The fMRI scans showed linkages between reading systems in the left hemisphere in non-impaired readers, while linkages between the left hemisphere and neural systems associated with memory in the right hemisphere were found in poor readers.

The diagnosis and treatment of dyslexia

Phonological processing isn’t only critical to written language, but also greatly influences spoken language. Therefore, although they may be more subtle, children with dyslexia can also show problems in spoken language. Furthermore, the clinical picture of dyslexia consists of reading problems, difficulties in handwriting and spelling, problems with mastering a foreign language and attentional problems. Reading fluency can be severely impaired in individuals with dyslexia thereby tremendously draining attentional resources. This makes attention a secondary problem next to the primary reading problems. On the other hand, dyslexia is highly comorbid with ADHD, which makes it a primary problem in some cases. In contrast to all those impairments, other cognitive abilities are usually intact.

Dyslexia is a clinical diagnose, best made by a trained clinician who uses history of the child, observes the child while reading and administers a battery of tests that assess the child’s cognitive abilities.

Effective reading instruction should include five essential elements, namely phonemic awareness, phonics, comprehension, awareness and fluency. These skills have to be taught systematically and explicitly. Early interventions for children with dyslexia have shown to be very promising in many studies. Classroom interventions, pullout remedial approaches and combinations of those two can improve phonological processing and initial word identification skills. Prevention programs that specifically focus on phonemic awareness, phonics and the meaning of text in the earliest stages of reading instruction reduce the base rates of at-risk students. Interventions for older students unfortunately show less promising results. It appears to be quite difficult to bring children or adults up to the expected grade levels once they fall behind, although significant improvements are still possible. Many studies have proven phonologically based decoding and word recognition to be teachable aspects of reading for most individuals. This evidence indicates that focused, intense, systematic and explicit interventions can positively impact word-reading development.

To increase fluency, fluency programs use repeated reading of connected text. More recent programs also focus on building semantic knowledge and orthographic pattern awareness. When these skills are improved, less strategic attention on the act of reading is necessary as it becomes automatic and therefore the reader can direct more cognitive energy and focus on comprehension and meaning.

Reading comprehension can be enhanced by strategy-related programs, which teach critical thinking skills related to understanding text and constructing its meaning based on the prior knowledge of the reader. The programs focus on finding ideas and facts, developing multiple meaning of words, summarizing text and increasing vocabulary. Unfortunately, applying those strategies in comprehension situations and new text reading has found to be a less consistent.

Although treatment plans can have a lot of positive effects, not all dyslexics respond to these programs. The dyslexia population is heterogeneous and there is no remedial instruction program that will cover the needs of all poor readers.

In order to help children with dyslexia to perform better at school, accommodations in the classroom are necessary. These accommodations occur in three different types:

1. Providing information through an auditory made, thereby by-passing the reading difficulties

2. Providing compensatory assistive technologies, such as computers

3. Provide students with additional time so that they can demonstrate their knowledge despite of dysfluent reading.

Abstract

This paper is about the relationship between ADHD and academic performance and covers the relationship at different developmental stages (pre-school, children, adolescents, adults) and the factors underpinning the relationship between ADHD and underperformance.

Introduction

Attention deficit hyperactivity disorder (ADHD) is a developmental, neurobiological condition defined by the presence of severe aand pervasive symptoms of inattention, hyperactivity and impulsivity [American Psychiatric Association (APA) 1994]. The concerned child must exhibit a number of inattentive, impulsive and hyperactive behaviours over a period of 6 months, before the age of 7, which should be present in school and at home, and which significantly impair daily functioning (DSM-IV criteria). The child has difficulties in taking turns, he talks excessively and often appears not to be listening when being spoken to. He also tends to interrupt and intrude on others in games, conversations and classroom discussions. ADHD exists in pre-school children, school-age children, adolescence and adulthood.

The co-occurence in ADHD is that 30-50% of ADHD children also have oppositional defiant disorder (ODD) and/or conduct disorder (CD). 20-30% of them experience anxiety and 11-22% also have bipolar disorder. 20-30% of the ADHD children additionally experience a learning disorder of reading, spelling, writing and arithmetic. ADHD children do have a decreased size of the prefrontal cortex and, therefore, experience for example deficits in response inhibition and working memory. ADHD is a disorder of dysregulation of thought and action associated with poor inhibitory control. It also is the manifestation of a motivational style associated with altered reward mechanisms. These two are independent coexisting characteristics of ADHD.

The academic disadvantage of ADHD individuals. A developmental perspective, from pre-school to university

The pre-school years are a key period for the ADHD children, because social, behavioural and  academic skills are developed for the success in academic performance. 2% of the pre-school children may experience difficulties in developing those skills as they are  identified  with ADHD. They may experience difficulties with memory, reasoning, academic skills, conceptual development, general cognitive ability and acquiring basic pre-reading and mathematics skills. Not all individuals who show early signs of ADHD go on to express fully the disorder and experience the associated academic impairments. A proactive, firm limit-setting at home and appropriately structured classrooms can help. However, once at school, children with ADHD will struggle with academic work. ADHD is associated with poor grades, poor reading and mathematics standardized test scores, and an increased likelihood of repeating a school year. The academic performance of adolescents with ADHD has faced less empirical scrutiny. However, it is suggested that they, too, are likely to struggle at school. Childhood hyperactivity has been shown to predict adolescent behavioural problems and adolescent academic problems, which tend to culminate in leaving school with no qualifications. Research shows that ADHD symptoms persist into adulthood, with between 11 and 40% of childhood cases continuing to meet criteria for the disorder in adulthood. Adolescent research shows that individuals with ADHD are likely to perform poorly at school, and leave with few or no qualifications, therefore university prospects seem bleak and are controversery. From a developmental prospective the negative impact of ADHD symptoms on academic attainment can be seen across the lifespan of children, adolescents and young adults.

Why do ADHD individuals experience academic problems?

As ADHD individuals often are likely to experience many other associated problems, such as a CD diagnosis, they are likely to experience future academic problems and offending problems. Also, research has shown that negative associations exist between ADHD and intelligence. 

Cognitive deficits and academic performance

The cognitive deficits – or executive function (EF) deficits – experienced by ADHD individuals include response inhibition and working memory. EF deficits are not common to all ADHD children. However, the implication of EFs in research suggests that deficits in executive functioning could be at the heart of ADHD-related academic underperformance.

Academic intervention

Inattentive symptoms and executive function (EF) deficitis, such as working memory , planning, and response inhibition, are associated with academic problems. Therefore, academic interventions should focus on these. The most common ADHD treatments include medication and behavioural interventions, from which the impact of academic performance is smaller and less studied. 

Peer and parent tutoring

Being placed in a large class may increase the ADHD childs' academic difficulties. In contrast, research on peer tutoring (a strategy whereby an ADHD individual is paired with a peer tutor to work on a certain academic activity, with the peer tutor providing one-on-one instruction and assistance at the ADHD individual’s own pace) has shown that it improves classroom behaviour and academic performance. Also parent-tutoring (through one-in-one instruction, feedback and active responding) may help to increase the reading performance at school and home. 

Task/Instructional modifications

Manipulating tasks through reducing the task length, dividing tasks into sub-units, giving explicit instruc-
tions, and modifying the delivery or modality of instruction according to the ADHD  pupil’s learning style may help in improving, for example, mathematics performance. 

Classroom functional assessment procedures

Developing an intervention, specific to the child, through manipulating environmental variables that initiate, maintain and/or increase the child’s problematic behaviour in a particular setting, could be used  to reduce disruptive behaviour in ADHD individuals.

Self-monitoring

Setting goals for classwork completion and accuracy, monitoring these goals and administering rewards upon successful completion may help the ADHD individual to improve academic performance, especially in combination with stimulant medication.

Strategy training

Teaching ADHD individuals a specific skill to implement in academic situations may help to improve their performance.

Homework-focused interventions

As homework is the best predictor of student grades and achievement, it may help to teach parents homework strategies based around the problems of ADHD individuals. However, parental ADHD levels should be taken into account. Altering teachers' attitudes towards ADHD behaviours may also help in generating a more positive classroom environment. 

Conclusion

ADHD is associated with academic underachievement from pre-schoolers to adults. Inattentive symptoms and executive function (EF) are associated with academic problems. Hyperactivity/impulsivity and co-morbid conduct problems are not. Future research should focus on the neuropsychological underpinnings of the relationship between ADHD and acadmic underperformance across the ADHD developmental spectrum.

Abstract

Research on executive functioning (EF) has been predominantly focused on preschool children. This paper outlines why it is important to examine EF throughout childhood and across the lifespan:

1. Examining EF in older children can address the question of whether EF is a unitary construct. 

2. Much of the development of EF, especially working memory, shifting, and planning, occurs after age 5.

3. Important applications of EF research concern the role of school-age children’s EF in various aspects of school performance, as well as social functioning and emotional control. 

Introduction

The prefrontal cortex (PFC) is critical to the planning, organization, and regulation of cognition and behavior. Executive function (EF) serves as an umbrella term to encompass the goal-oriented control functions of the PFC. Relatively complex neuropsychological instruments such as the Wisconsin Card Sorting Test (WCST) were first employed to evaluate frontal lobe functioning and later to assess EF. Research with a focus on preschoolers is great, because such work identifies the very beginnings of each component of EF. Also, as it is needed to work with simplified tasks, suitable for young children, it is possible to assess a single EF component, thus avoiding the problem of task impurity. Finally the focus on preschoolers has revealed important relations between EF and theory of mind. However, assessing EF in school-age children allows us to ask questions that cannot be answered in research with preschoolers. Research on further changes in the development of each EF component and in the relations among the components during later childhood and adolescence would not only clarify EF as a construct but also provide insight into processes underlying the development of EF. Furthermore, significant improvements in EF tasks occur during the school years. It is, therefore, important to examine EF in school-age children in order to get a developmental picture of EF. As with studying the developmental trajectories of EF components in childhood and adolescence, the course of typical EF decline should clarify the interaction of EF components to produce goal-oriented behavior and the nature of brain processes supporting EF.

Like brain development in general, PFC development involves both progressive (e.g., neuron proliferation, synaptogenesis, myelination) and regressive (e.g., cell death, synaptic pruning) changes. The general finding that EF (behavioural development) develops throughout adolescence is affirmed by the protracted development of the PFC (neural development).

EF as a construct

In order to explore EF as a construct, it is necessary to involve older children and adolescents as well as preschoolers in research. Two questions arise:

1. Is EF best thought of as a unitary process or as a set of multiple, distinct component processes?

2. If EF does refer to distinct component processes, how are these processes related and how does this relationship change as the child develops?

Concerning the first question: Most studies support the view that EF consists of related but separable components (which is also called the unity-but-diversity view) and purport that a common mechanism (or mechanisms) underlies all EF processes. Other evidence supports the unity-but diversity view through, first, showing that the different developmental trajectories over childhood and adolescence undermine the notion of a completely unified EF. Second, through neuroimaging research that indicates that multiple EF tasks that span different EF domains recruit slightly different regions of the PFC. Third, through research at multiple time points and finally, through the fact that a particular deficit, such as poor academic performance in a specific area (see below) is associated with a greater impairment for some EF components than others, which suggests some independence. A remaining methodological challenge is to create EF tasks that isolate and assess one or the other EF component.

Concerning the second question: Structural equation modeling (SEM) is used as a method that allows the researcher to examine what (and how) EF domains are recruited during complex problem solving. Research shows, that the relations among EF components change with age. Knowledge of what EF skills are recruited during successful completion of complex problem solving is important not only for theoretical reasons, but also for practical ones, such as developing interventions for school children with poor EF. This knowledge can only be gained through including older children and adolescents, as well as preschoolers in research.

The developmental trajectories of EF's

Inhibition

Inhibition commonly refers to the ability to suppress a dominant, automatic or prepotent response, but inhibition also entails interference control, directed forgetting, emotional control, and motor control. Research documents rapid improvements in early childhood on tasks such as the Day/Night task, Luria’s fist and finger game, and the A-not-B task. In the preschool years children significantly reduce their inhibition errors. Although improved inhibition during the preschool years is striking, significant improvements also occur later, particularly between ages 5 and 8. Unlike the fundamental changes during preschool, changes during adolescence mainly consist of refinements in speed and accuracy. Behavioral improvements in inhibition appear to be paralleled by refinements in the underlying brain activity in the PFC and in networks that include the PFC. Neuroimaging (fMRI), EEG and Diffusion Tensor Imaging (DTI) suggest that in addition to the focalization and migration of activity, perhaps increasing connectivity of frontal brain regions serves to enhance inhibition in later childhood.

Working Memory (WM)

Generally speaking, WM involves the ability to maintain and manipulate information over brief periods of time. Research shows a linear increase in performance from age 4 to 15 for a battery of WM tasks of varying complexity. The age-related changes in performance depended on the complexity of the particular task. Thus, it is important to consider the complexity of the task when extrapolating a general trajectory of WM development. Research shows that WM development apparently continues through adolescence, and easier WM tasks are mastered before more complex ones. Neuroimaging studies also point to continued changes in brain activity associated with WM through childhood and adolescence. Results of the studies suggest further refinement of WM through adolescence as the prefrontal regions become more specialized for WM. Paralleling the behavioral findings on inhibition, these results suggest that the large improvements in WM in early childhood, along with qualitative changes in brain recruitment, are followed by more subtle refinements consisting of quantitative changes in activation and focalization of brain regions related to WM.

Shifting

Shifting regards the ability to shift between mental states, operations, or tasks. The WCST is the classic shifting task, whereby the participant is asked to sort cards based on a specific dimension (e.g., shape). Then,  the sorting rule changes and the participant must determine the new sorting rule (e.g., color) and sort accordingly. Successful task switching involves inhibition of previously activated mental sets. The ability to shift between more complex task sets, each with more numerous and complex rules improves with age, typically until early adolescence. Shifting ability may be measured in terms of shift cost, which is the difference either in response time or accuracy between shift trials and non-shift trials. Results show an increasing awareness of the relationship between speed and accuracy in childhood. This suggests the emerging presence of metacognition and its contributions to developmental differences in task performance. Mature task shifting is related to inferior frontal and parietal regions as well as superior temporal regions in adults. 

Planning

Planning is a critical part of goal-oriented behavior; it embodies the ability to formulate actions in advance and to approach a task in an organized, strategic and efficient manner. Tasks that evaluate planning ability require the child to prepare multiple steps of action in advance, to evaluate those actions, and to change course if necessary. The most frequently used tasks are the Tower of Hanoi (TOH) and the Tower of London (TOL). The particular age at which mastery is reached depends on the difficulty of the TOL or TOH task condition. The ability to effectively plan up to three moves is present by middle childhood, but the ability to effectively create more complex plans of 4 or 5 moves seems to develop at some point in late childhood or adolescence. Thus, planning ability seems to follow a protracted developmental course such that performance improves at least into late childhood and often adolescence. Little is known about the brain changes related to the development of planning skills.

Aging and executive function

EF seems to be particularly vulnerable to age-related cognitive declines. In contrast, non-executive abilities such as procedural memory, vocabulary, and numeric abilities are relatively spared by the aging process. In accord with the specific vulnerability of EF, normal aging is not characterized by widespread neural changes but instead by selective cell loss, dendritic deterioration, and chemical dysregulation in the PFC and hippocampus. Research suggest that with age dopamine (DA) projections to the dorsolateral preforantal cortex (DL-PFC) are disrupted, causing impairments to the gating mechanism. Such disruptions equally impair WM and inhibition, which supports the finding that performance on a variety of executive tasks deteriorates with age. Multiple executive processes begin to show impairment by the 7th decade of life. Functional neuroimaging studies point to the complexity of the neural correlates of EF. 

Conclusions

Inhibition shows prominent improvement during the preschool years and less change later on. WM and shifting, on the other hand, appear to emerge in the preschool years but really improve the most afterwards in a more linear fashion. Planning ability, which typically is measured by more complex tasks, seems to make the largest gains in later childhood or adolescence. EF is particularly vulnerable to the aging process as multiple executive processes (e.g., resistance to interference, WM) begin to show impairment by the 7th decade of life.

Uses of executive function in daily life

After age 5, children enter more social settings and go to school.

Social functioning and emotional control

The same general brain structures appear to underlie both cognitive and emotional processing. EF appears to be related to social and emotional self regulation. The link between one aspect of self-regulation, effortful control (which includes attention control, inhibitory control and low-intensity pleasure and is assessed by the Children’s Behavior Questionnaire), and EF is likely due to the development of the anterior attention network. Attention training may improve children’s cognitive and emotional regulation. The link between EF and social functioning continues during aging. 

School performance

EF might affect school performance (e.g. through not being able to remember instructions, performing mental calculations, poor writing, unmoral behaviours or language impairment, which is associated with WM). In turn, by providing situations that encourage EF practice, EF development may be facilitated, too. By expanding EF research to school-age children, the relations to an important aspect of childhood—schooling—can be examined. Different academic activities (e.g., mathematics, reading, and writing) appear to involve different combinations of EF components. Attempts to uncover causality between EF and school functioning have been inconclusive. Likewise, more research is needed to reveal the contextual factors (e.g., type of classroom environment) that enhance EF. Once these relations are clarified, interventions can be developed to bolster the specific EF domains underlying each academic skill.

Conclusions and directions for future research

EF as a construct

We know that the specific relations among the various EF components change across development, which suggests that the components are somewhat separate, even though related. Future research could employ a training study design in order to address whether EF consists of largely independent components or a single, unified ability.

Developmental trajectories of each EF component

The review of subsequent developments shows continued improvement of all components, probably even into adolescence, as well as somewhat different developmental trajectories for each component. Particular sorts of studies with school-age children and elderly adults would be especially useful for examining key questions
about development. These may for example clarify why children of different ages differ in the particular components of EF they find difficult to recruit.

Uses of EF in daily life

Research has shown a possible link of EF to social problems. Although peer relationships are known to become increasingly important during middle childhood and adolescence, we know little about the connections between EF and peer interaction. The work on older children expands the domains for which EF might be important, in particular, formal schooling. The EF components appear to be related differentially to various academic subjects. In both children and adults, inhibition and updating of WM, but not shifting, are related to monitoring performance in a time-based prospective memory task. More research and theorizing on EF in children older than 5 would provide a more complete picture of the development of EF. Such work would shift the research focus from the early emergence of EF to its refinement and application to daily life.

There has little to no research conducted that addresses school-based interventions to give teachers some tools to handle children in their classroom with ADHD. This lack of information is partly due to the fact that ADHD is conceptualized as a psychiatric construct, and thus it is most often approached from a medical perspective.

Most of the responsibility for meeting educational needs of children with ADHD lies with their general education teachers, while this particular group in several researches expressed that they need assistance and more information about managing children with ADHD. Currently, most schools do not have a general approach to handle classroom problems caused by children with ADHD systematically. Also, teachers mostly rely on punishing approaches only and tend to deny the problems of children with ADHD.

A solution for these problems could be the multimodal model, which involves coordinated treatment planning by all involved parties (parents, teachers, psychologists etc.). The model incorporates different kinds of treatments such as medical approaches, behavior modification, educational accommodations and psychological support. There is a considerable amount of research that has shown the effectiveness of the multimodal model.

Functional assessment is an approach to the multimodal treatment of ADHD which focuses on manipulating the environment variables to determine the best conditions under which children may perform appropriate classroom behaviors. Thereby it empowers teachers to fulfill the following three goals:

1. Prevent inappropriate classroom behavior from occurring by analyzing and modifying environmental events.

2. Determine what children try to achieve with their inappropriate behavior and seek for replacements of appropriate behavior with a similar function.

3. Develop interventions which enables children with ADHD to perform socially desirable classroom behavior.

Overview of the traditional approach and its critique

The goal of traditional assessment is quite the same as that of functional assessment, but the traditional assessment has had little implication for changing the behavior of ADHD children. Traditional assessment is based on Cronbach’s ideas about correlation. He hypothesized that the aptitude by treatment interaction approach (ATI) was the most effective way for assessment. This approach is based on the two principles that (1) inappropriate behaviors are due to underlying characteristics of the individual and (2) it is necessary to identify the underlying trait that is causing the behavior in order to remediate the behavior. Unfortunately, correlation was erroneously equated with causation. When there is relation between two variables, it doesn’t necessary mean that the one variable caused the other to occur. Therefore it is very uncertain to select an intervention based on a prediction from a variable. The effectiveness s ATI has never been proven and consequently is not a functional approach. The same thing can be said for a lot of current treatments for ADHD; token strategies, classroom interventions and even Ritalin cannot be differentiated between children with and without ADHD.

When Cronbach realized that ATI didn’t work, he replaced it with a context-specific approach. The main difference between those two approaches was the shift from aptitudes to context. Seen from the ecological perspective, which considers environment and behavior as a ongoing interaction, context provides meaning to behavior. The best way to change a child’s behavior is to take the context under which these behaviors occur into account. The context-specific approach focuses on the outcomes of interventions. The child gets the best possible treatment, the desired progress gets observed and if the treatment doesn’t work it gets modified.

Overview of the functional perspective

The functional perspective is a logical extension of the context-specific approach. It addresses the interaction between specific behaviors of a child and the environmental factors. These specific behaviors are cued by antecedents and decreased, increased or maintained by followed consequences. Therefore the purpose of functional assessment is to find the relation between behavior and the environment, and hereby identifying the most effective method to modify behavior.

Stages of functional assessment

An approach that has shown to be effective for classroom use in several studies is the framework developed by Dunlap and Kern. Their approach consists of three levels: hypothesis development, hypothesis testing and intervention development.

Hypothesis development is a process that should embody three activities and thus consists of three stages:

1. Developing a precise definition of the behavior in question.

2. Collecting information during the conditions under which the specific behavior occurs.

3. Analyzing whether the information obtained shows any patterns that might indicate a functional relation.

There are a few conditions which a definition of behavior should meet to qualify as well-defined. First, it should pass the ‘stranger test’. This means that a stranger should be able to determine when a behavior occurs does or doesn’t occur on basis of the definition, in reasonable agreement with those observations of the teacher. Second, a behavior should pass the ‘so what test’. This implies that behavior that doesn’t interfere with the learning targets of the child with ADHD or its peers should be ignored. Because a child with ADHD shows many behaviors that could be a target for intervention but time and resources are limited, this is very important. Also, this minimizes the effect of the teacher’s own standards of what is normal. Third, a good target behavior is one that is also a ‘fair pair’. This concept states that for every inappropriate behavior that should be decreased, there’s an incompatible behavior that should be targeted to increase. Finally, the description should pass the dead man’s test. This test shows whether a fair pair is targeted. If a dead man can perform the target behavior, then you do not have a fair pair. If he cannot, you do.

Information can be collected through multiple techniques such as interviews, observation, archival records and rating scales. Any functional assessment should include direct observation and interviews because these are the most reliable sources of information. However, most of the time it’s very useful to start an investigation with examining archival records and completing behavior rating scales. The latter two can be used to get a fix on the problem and thereby help select behaviors and settings most salient for observation. Furthermore, it’s advisable to interview multiple people to determine in which settings certain behavior does and doesn’t occur. This information gives a contextual starting point to formulate hypothesis which can be tested using direct observation methods. The most ecologically valid assessment technique is to define the target behaviors, observe and record their occurrence or nonoccurrence in their natural environment and analyze this data. This not only confirms or denies expectations about relationships between environments and certain behavior, it also provides baseline information about the behavior before treatment. The most commonly used method to do a functional assessment behavioral observation is an antecedent-behavior-consequence analysis (ABC).

Next, it’s important to collect information on behavioral intent. Why does a child perform certain behavior and what does it want to achieve with its acts? In order to determine these intentions, the Outcome Analysis Worksheet was developed. This is quite similar to the ABC-analysis with the added component of hypothesizing on the possible outcome. As from now, replacement behaviors – appropriate behaviors to replace the inappropriate – can be conducted for hypotheses testing.

Hypotheses testing aims to identify the conditions where the variables thought to be related to the behavior can be controlled and manipulated directly. This can be done using in vivo (naturalistic) or analogue (role play) assessment.

In vivo assessments observe students performing the target behavior in their natural habitat while the practitioner systematically controls and manipulates situational and contextual events. In order to determine the validity of the hypothesized functional relation, multiple observations would be required. Disadvantages of this approach are that it’s difficult to control all situational variables, and that target behavior must occur during the observations while not all naturalistic situations encourage children to perform the target behavior.

The analogue assessment involves a role play in which a child’s behavior during staged situations gets observed. The advantage of this approach is that target behavior can be elicited and observed while situational and contextual events are controlled or manipulated. Analogue assessment also has a therapeutic value, for students with ADHD might learn appropriate behavior from their peers. When they receive reinforcement from children their own age, they are more likely to perform this appropriate behavior more often. The limitation of this approach is that because of the artificial nature of the method, the information obtained often doesn’t correspond with naturalistic observations. It is therefore recommended to use the analogue assessment combined with in vivo assessment.

It takes a lot of time to test hypotheses, and consequently, teachers often tend to skip this step. However, it takes even more time to implement ineffective accommodations and interventions which have to be changed afterwards. Determining which environmental variables have the greatest impact on a child’s behavior can help to avoid this.

Accommodations and interventions

Information obtained from testing hypotheses can be translated into accommodations and interventions by using the most important variables that have come forward from the testing and operationalizing them into specific, practical interventions. The process of testing hypotheses should be seen as part of the intervention process, because the environmental variables are constantly being manipulated while observing their effect on behavior.

Manipulating antecedents is a form of prevention. Most classroom accommodations focus on antecedents to prevent inappropriate behavior from occurring, a proactive strategy. Changing antecedents can result in a major change of behavior and usually arise from logically thinking, therefore they are practical, simple to implement and require minimal time.

of the categories of accommodation is the physical location of a child in the classroom. This may have to do with where the student is seated, group composition, activity grouping (group vs. independently working) and the type of work station a child gets assigned to (lots of materials on it?). There’s a new approach for children with high motor activity, which provides them with multiple desks: one in the front of the classroom and one on each side of the back of the room. That way, when a child feels restless it can pick up its stuff and move to another part of the classroom. Most important when implementing accommodations is to be flexible, creative and broad-minded.

The manipulation of task material can also be very useful. The amount and type of feedback provided during task performance, degree of stimulation, the response mode, the degree of task structure and the amount of interest students show in a task are all variables worth manipulating to enhance appropriate behavior.

Letting students with ADHD complete assignments independently can lead to a few problems. They might not have the skills to work independently. It is very important to ensure that a child with ADHD fully understands the assignment before moving to independent practice activities. Teacher-led small-group question and answer sessions is a method to clarify the degree of accuracy in which the student has mastered the concept. Furthermore, students with ADHD can experience some difficulty in obtaining help during seatwork activities, or the teacher is unable to provide assistance at that very moment. To asses this problem, teachers can construct assistance cards. On one side of the card, the teacher writes ‘Please help me’, and on the other side ‘Please keep working’. When a child is in need of assistance, it can flip the card to ‘Please help me’ and but it on his table. If the teacher isn’t able to provide help at that moment, he can flip the card to ‘Please keep working’. He thereby acknowledges the child’s request, and the child knows the teacher will assist him as soon as possible. Finally, children with ADHD often misbehave when too much work is required during independent seatwork. Short assignments and frequent breaks can be helpful. It’s very important that breaks or transitions are highly structured.

Curricular instructions can also be manipulated and thereby prevent certain behavior from occurring. The curriculum is a structured set of learning outcomes. To accommodate students with ADHD, the sequence of the curriculum may be shuffled, its tasks may divided into smaller pieces or combined into larger ones, organizational structure can be altered and different instructors may help to teach the program. The most important factor to make children feel involved with the curriculum, is to make them see the learning material as meaningful. The otherwise short attention-span of children with ADHD is much longer when they are engaged in high-interest activities: also called the Nintendo-effect. When de study material gets linked with topics that interest the child, they will try a lot harder to engage.

The length, format and difficulty of lessons can me modified to better fit the needs of a child with ADHD. Giving students the opportunity to answer questions they’ve been asked instead of letting them wait for a long time before they can respond is crucial for their engagement.

Instructional strategies are meant to enhance a student’s acquisition. Cognitive strategy instruction teaches students to use self-instructions and mental imagery to accomplish academic tasks independently. Mnemonic instruction is a related strategy and designed to improve memory. By reconstructing study material and connecting it to existing knowledge of the student, they remember the content better. By using the students frame of reference, they add a personal meaning to the task. Peer tutoring also seems to be a relative technique.

Moving from one group, classroom, activity or subject to another is called a transition. By setting aside certain times on which the transitions are performed, establish the expectation that the students move quickly from one place to another and tell them that any lost time is made up during free time, transitions become more efficient and instructions more effective.

We call events that follow behavior consequences: they can increase, decrease or maintain certain behavior by ignoring, punishing or reinforcing. When a certain behavior is ignored, an appropriate behavior should be reinforced. In order to effectively ignore undesired behavior, the child performing the behavior should also be excluded from positive or negative attention from its peers. Punishment is not very effective when it’s not combined with positive reinforcement, which focuses on increasing desired behavior. 

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention and/or hyperactivity-impulsivity. Approximately 5 to 7% of all children meet criteria for ADHD. Due to inattentive and disruptive behavior in class, children with ADHD are at risk of academic difficulties, including underachievement, retaining grade, special educational placement, and suspension or drop-out from school. As ADHD related behaviors may disturb the learning process of classmates and may elicit maladaptive behavior of both classmates and teacher, overall classroom functioning may decrease, both academically and socially.

Teachers play an important role in considering interventions. They may be confronted daily with children with ADHD and they need to have the ability to manage these children. Providing teachers with effective tools may benefit children with ADHD as well as their classmates, but moreover, may improve confidence and wellbeing of teachers themselves. As the most common treatment for children with ADHD is stimulant medication, which is limited by several factors (e.g. side effects, compliance problems), there is a need for non-pharmacological interventions, including school-based interventions. 

Previous studies on the effectiveness of school-based interventions show inconsistent results. 

The present study

The present study provides a meta-analytic review of published studies on classroom interventions for ADHD covering a period of 33 years of research. It aims to first, determine the effectiveness of several types of classroom interventions (antecedent-based, con-sequence-based, self-regulation, combined) that can be applied by teachers in order to decrease off-task and disruptive classroom behavior in children with symptoms of ADHD, second, to identify potential moderators (classroom setting, type of measure, students’ age, gender, intelligence, and medication use) and third, to qualitatively explore the direct or indirect affect of the classroom interventions on behavioral and academic outcomes of classmates.

Method

The guidelines for Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) were followed.

Inclusion and exclusion criteria

For the review, the studies needed to meet the following inclusion criteria:

1. Written in english

2. Participants attended grade 1-12 and had ADHD/ADD difficulties and an IQ of 70 or above

3. Intervention had to be implemented by the teacher in the classroom and required no prental involvement

4. The interventions could be classified into one or more out of these categories:

   1. Antecedent-based intervention: An intervention that manipulates antecedent conditions, such as the environment, task, or instruction (e.g., seating, music, tutoring, choice making, computer-assisted instruction)

   2. Consequence-based intervention: An intervention that uses reinforcement and punishment to alter the frequency of target behavior (e.g., praise, reprimands, prizes, privileges, response-cost)

   3. Self-regulation intervention: An intervention aimed at the development of self-control and problem-solving skills to regulate cognition and behavior (e.g., self-instruction, self-monitoring, self-reinforcement)

5. The outcome measures were either teacher ratings or direct observations of off-task behavior (e.g., not attending to task or teacher, looking around), disruptive behavior (e.g., disturbing classmates, playing with objects, out of seat), and ADHD behavior (e.g., teacher rating on an ADHD rating scale) in the classroom.

6. The study could be classified into one of the following categories of experimental design categories:

   1. Between-subjects group design: A design that uses an intervention group and a non-intervention control group.

   2. Within-subjects group design (WSD): A design that applies the same intervention on each participant and assesses outcomes on at least two occasions.

   3. Single-subject design (SSD): A design that documents changes in behavior for an individual participant during intervention phases and non-intervention control phases.

7. Sufficient data were provided to compute effect sizes.

Search procedure

It was systematically searched for literature through online databases and manuals.

Coding procedure and moderating variables

Each study meeting inclusion criteria was systematically coded on several variables by the first
author. Variables that were examined as potential moderators included intervention type, classroom setting, type of measure, and characteristics of participants receiving the intervention, including age, gender, intelligence, and medication use. The categories antecedent-based, consequence-based, self-regulation, and combined were used to classify intervention type. The following codes were used:

• Classroom setting - general education or other

• Type of measure: teacher ratings, direct observations, or both

• Participants: children or adolescents, gender, IQ

• It is looked at the study quality (high quality, acceptable quality, unacceptable quality) and secondary quality indicators (evidence or no evidence). 

Statistical analyses

SPSS is used for the statistical analyses. Separate meta-analyses were performed on standardized mean differences (SMDs) for 24 within-subjects design (WSD) and 76 single-subject design (SSD) studies.

Results

A total of 4,553 records were identified through electronic databases and an additional 230 records were identified by the manual searches. A total of 89 articles meeting inclusion criteria were considered in the present meta-analytic review, yielding to 100 studies. 

Study characteristics

Different study characteristics are summarized in the article. These are year of publication, experimental design, examination classmates (yes or no), type of measure, intervention type, classroom setting, number of participants, age, a differentiation between children and adolescents, gender, IQ, medication use, and study quality. (see table in the article for more details)

The majority of WSD (within-subject design) studies (83%) obtained a weak rating of study quality and half of the SSD (single-subject design) studies (54%) had an adequate study quality and 43% were rated as weak.

Within-subject design studies

Effect sizes for WSD studies ranged from −0.08 to 3.00 (Winsorized value) with a median of 0.92. The mean weighted effect size was 0.92 and reached significance (95% CI [0.59, 1.25]).

Single-subject design studies

Effect sizes for SSD studies ranged from 0.42 to 7.00 (Winsorized value) with a median of 2.63. The mean weighted effect size was 3.08.

Direct effects on classmates

For all four WSD studies applying antecedent-based interventions, effect sizes for behavioral outcomes of classmates were positive, ranging from 0.21 to 1.97. Positive effects on classmates were also found for all four SSD studies.

Indirect effects on classmates

Positive indirect effects on behavioral outcomes of classmates were found for two out of three studies.

Discussion

Regarding the first aim of this study: The results indicate that classroom interventions reduce off-task and disruptive classroom behavior in children with symptoms of ADHD, which is in accordance with previous meta-analyses. It is indicated that interventions implemented in general education classrooms lead to a larger reduction in off-task and disruptive classroom behavior in children with symptoms of ADHD than interventions implemented in other classroom settings. 

Regarding the second aim of this study: no reliable conclusions can be drawn about potential moderators.

Regarding the third aim of this study: Results imply that classroom interventions for children with symptoms of ADHD have both direct effects on classmates, i.e., improvement of classmates’ behavior because they also benefit from the intervention, and indirect effects on classmates, i.e., profit from less classroom disturbance by children with symptoms of ADHD.

In summary

Results showed that classroom interventions reduce off-task and disruptive classroom behavior in children with symptoms of ADHD. No reliable conclusions could be formulated about moderating effects of type of measure and students’ age, gender, intelligence, and medication use, mainly because of power problems. Finally, classroom interventions appeared to also benefit classmates’ behavioral and academic outcomes.

Limitations

First, the meta-analytic review was restricted to studies published in academic journals. Second, there was a trend for the smaller studies to show larger treatment effects than the larger studies. Third, most studies employed SSDs, for which exact expressions of effect size variances have not been derived. Fourth, potential moderators had to be analyzed using subgroup analyses instead of meta-regression analysis because the data were not normally distributed and therefore violated the assumptions for regression analysis. Finally, the results are most representative for boys in the age of 6 to 11 years, as only a minority of studies reported about samples including females and/or adolescents.

Future Research

First, girls should be more included in research onthis field, second, additional factors influencing the effectiveness of classroom interventions for children with symptoms of ADHD should be further examined, and finally, there is a need for higher quality studies in this field.

Implications for practice

As this review shows that teachers can effectively implement classroom interventions to reduce off-task and disruptive classroom behavior in children with symptoms of ADHD, it is important that classroom management training is offered to teachers.

Conclusion

This review indicates that classroom interventions reduce off-task and disruptive classroom behavior in children with symptoms of ADHD. WSD studies showed that consequence-based interventions are more effective than antecedent-based, self-regulation, and combined interventions. However, SSD studies showed largest effects for self-regulation interventions. Larger effects were obtained for children with symptoms of ADHD in general education classrooms than for those in other classroom settings. No reliable conclusions can be formulated about moderating effects of type of measure, and student’s age, gender, intelligence, and medication use. Finally, the study also indicates positive direct and indirect effects of these classroom interventions on classmates’ behavioral and academic outcomes. The results of this study may be used for educating and training teachers in dealing with children with symptoms of ADHD.

Introduction

The body of research studies evaluating the potential for physical activity (PA) to improve ADHD symptoms and functioning, especially those employing well-controlled designs, is quite limited. This review gives evidence for the potential benefits of promising research in this field, as well as five key points that researchers and practitioners should keep in mind while reading and evaluating this evidence.

Point I: From neuroscience and developmental perspectives, there is reason to be optimistic about the potential of PA for improving ADHD symptoms and functioning

From a brain science perspective, research shows that PA may promote more adaptive functioning in individuals with ADHD (e.g. changes in neurotransmitter levels, enhanced cerebral capillary growth and blood flow to the brain, promotion of neurogenesis, and growth in brain tissue volume). PA may have a corrective effect on neurodevelopment for those at risk for ADHD, potentially preventing or altering the course of the
disorder.

Point II: Despite this optimism, the amount of actual wellcontrolled research employing designs that meet strict research standards is quite limited

In discussing the PA intervention literature, an important distinction is made between acute and chronic applications of PA. As the goal of the review is to consider the evidence for the use of PA to manage ADHD symptoms over the long term, the discussion is restricted to studies of chronic effects of PA. Unfortunately, the literature is quite limited.

Current status of the literature 

The current status of literature show limitations, that include small sample sizes, nonrandom assignment to conditions, insufficient control groups to rule out competing interpretations of results, raters not blind to condition, and biased analyses that only consider treatment completers.These limitations reflect the level of difficulty associated with fitting chronic PA studies into the rigid confines of well-controlled research.

Point III: The limited amount of research conducted to date reflects the difficulties associated with venturing beyond the ivory tower to conduct the type of research that is needed

Studies of chronic PA, administered multiple times per week, are most likely to succeed in the settings where children live their daily lives. Three key challenges are particularly daunting in research conducted in natural settings:

1. Random assignment to condition

2. Blinded raters

3. Adequate control groups

Point IV: Despite these limitations, the current literature shows promise

For all categories of outcomes, in order to consider PA as beneficial, either (1) a statistically significant between-groups effect or time by treatment interaction or (2) a reported between-groups or simple effect size (Cohen’s d) of at least .20 favoring PA is required.

What we know:

1. In most studies, aerobic PA shows beneficial effects on parent- or teacher-rated ADHD symptoms

2. PA shows benefit on a variety of cognitive capacities, measured primarily using neuropsychological or executive function (EF) tasks.

3. Systematic PA appears to benefit additional functional domains in ADHD (social functioning, motor skills, behavior, and the affective/emotional domain)

4. The benefits noted above are derived from studies using unmedicated participants, medicated (for ADHD) participants, and studies where medication is not systematically considered

5. In at least one study, beneficial effects of PA are associated with measurable changes in brain activity

Point V: What we do not know is just as important as what we know

What we do not know about PA as a symptom management strategy for ADHD:

1. What is the optimal “dose” in terms of individual session length and frequency, and program length, for obtaining PA effects in children with ADHD?

2. Is there an age when the effects of PA are optimized?

3. How does PA perform when compared directly to established treatments for ADHD?

4. Do the effects of PA persist beyond the period of time when PA is actively administered?

Conclusion

Much more is unknown than is known about PA as a management strategy for ADHD. However, preliminary work suggests beneficial impact in multiple areas of dysfunction, with none of the available studies reporting adverse effects. There is currently insufficient research to warrant recommending PA as a sole intervention; an adequate body of well-designed research studies is greatly needed.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with core symptoms of inattention, hyperactivity, and/or impulsivity and has a prevalence of 9.5% for 4-to 17-year-olds in the United States. Executive functioning is typically impaired in children with ADHD, affecting their academic achievement. Computer Attention Training is used to decrease ADHD symptoms and improve executive functioning skills. Two types of CompAT interventions were evaluated in the current study: neurofeedback and cognitive training (CT). Neurofeedback trains users to monitor and change their brainwave patterns, leading to behavioral changes. CT uses specifically designed exercises to train attention, working memory, and impulsivity through ongoing feedback to reinforce correct responses.

Methods

Participants

Students with ADHD attending 1 of 19 public elementary suburban or urban schools in the Greater Boston area were eligible to participate in the randomized trial. Inclusion criteria in-cluded the following:

1. Child in secondor fourth grade

2. Clinical diagnosis of ADHD made by the child’s clinician

3. Ability to speak and understand English well enough to follow the protocol

One hundred four children were randomly assigned to receive neurofeedback, CT, or a control condition and were evaluated 6 months postintervention.

Interventions

Participants received in-school 45-minute intervention sessions 3 times per week, monitored by a trained research assistant (RA), for 40 sessions over 5 months.

Primary Outcome Measures

Outcome measures included parent reports of ADHD symptoms and executive functioning, medication use, and systematic classroom observations of behavior. All outcome measures were obtained pre- and postintervention, and 6 months later. A 3-point growth model assessed change over time across the conditions on the Conners 3–Parent Assessment Report (Conners 3-P), the Behavior Rating Inventory of Executive Function Parent Form (BRIEF), and a systematic double-blinded classroom observation (Behavioral Observation of Students in Schools).

Data Analysis

Because this study investigated whether the 2 CompAT interventions are superior to community treatment alone, and whether neurofeedback is superior to CT, the randomized controlled trial is considered a superiority trial and analyses are presented with 1-tailed tests. The central focus of the analyses was to evaluate whether the observed changes in core ADHD symptoms between the startand end of the treatment period were sustained at the 6-month follow-up. Comparisons between neurofeedback and CT were undertaken using multivariate general linear hypothesis tests. Paired t tests were conducted to evaluate stimulant medication differences in methylphenidate equivalencies within randomization conditions between pre-intervention and the 6-month follow-up. An analysis of covariance was conducted to evaluate medication dosage differences among the randomization conditions at 6-month follow-up. 

Results

Of the 104 children in the study, 102 completed the intervention. Of these, only 4 did not complete the 6-month follow-up assessment. At baseline, 95% of participants showed clinically significant scores on the DSM,
Fourth Edition, ADHD Inattention and/or ADHD Hyperactive-Impulsive subscales. At baseline, 49% of participants were taking medication.

Growth Model Analysis

Parent-Reported Measures

Six months postintervention, neurofeedback participants maintained significant gains on Conners 3-P (Inattention effect size [ES] = 0.34, Executive Functioning ES = 0.25, Hyperactivity/Impulsivity ES = 0.23) and BRIEF subscales including the Global Executive Composite (ES = 0.31), which remained significantly greater than gains found among children in CT and control conditions. Children in the CT condition showed delayed improvement over immediate postintervention ratings only on Conners 3-P Executive Functioning (ES = 0.18) and 2 BRIEF subscales.

Classroom Observation

There were no differences found between neurofeedback and CT conditions on classroom observation measures. 

Medication Analysis

At the 6-month follow-up, neurofeedback participants maintained the same stimulant medication dosage, whereas participants in both CT and control conditions showed statistically and clinically significant increases
(9 mg [P = .002] and 13 mg [P , .001], respectively).

Discussion

The outcomes of the analyses are promising, as children in the  neurofeedback condition reported sustained improvements 6 months after the intervention, compared with those in the control condition. In the CT condition, areas of executive functioning that did not show statistically significant change immediately after the intervention showed a significant change by the 6-month follow-up assessment compared with the control condition. The inclusion of the systematic classroom observations provided a valid double-blinded representation of the children’s behavior in the classroom. This study used multiple sources and types of data including questionnaires from parents, systematic classroom observations of behavior, and medication.

Conclusions

Neurofeedback participants made more prompt and greater improvements in ADHD symptoms, which were sustained at the 6-month follow-up, than did CT participants or those in the control group. This finding suggests that neurofeedback is a promising attention training treatment for children with ADHD.

A lot of parents, teachers and health care professionals find that despite of the large amount of research on ADHD, the disorder is often over-diagnosed and children get over-medicated. They question the validity of diagnosis and emphasis the importance of collaboration between health care professionals, the educational system and family. The knowledge and perspectives on ADHD of all individuals involved highly influences the process of identification, referral, diagnosis and treatment of children with ADHD. It’s essential to address differences in perspectives in order to achieve a common goal and shared understanding.

There still seem to be a lot of misunderstanding about ADHD, even among teachers, physicians and parents. Some still believe ADHD to be the result of bad upbringing, think a chaotic and dysfunctional family is the etiology of ADHD, don’t know about the importance of genetic factors, believe in a sugar etiology or think children with ADHD misbehave because they don’t want to obey rules.

Research into the perspectives of children against ADHD found that some children viewed ADHD as a disorder of academic achievement (performance niche)while the others thought it to be a disorder of aggression and anger (conduct niche). The study was performed amongst 151 children who were diagnosed with ADHD or did not have any psychiatric diagnosis. The children in the performance niche (mostly found in the USA) wanted to do well and felt that medication helped their academic achievement. Children in the conduct niche (mostly found in the UK) wanted to be ‘good’ and expected stimulants to improve their self-control.

Children and adolescents with ADHD and their parents often feel stigmatized which greatly influences their self-esteem and the effect of their treatment. Especially adolescents seem to be more prejudiced and less accepting towards individuals with ADHD. Parents often show their concerns about the fact that they feel they and their child are being labelled by society and thereby rejected and isolated. New insights into the experience of stigmatization amongst children was found in the VOICES study. The children in the performance niche didn’t experience a lot of stigmatization, bit did fear it. Children in the conduct niche did experience stigma related to having an ‘anger problem’. Children with ADHD are increasingly using online social networks to neutralize stigma. Parents sometimes felt stigmatized for having a child with the diagnose of ADHD and accepting medication as a treatment (courtesy stigma). In teachers, the label ADHD increases the perception that the behavior of a child is disruptive and that they would have trouble handling the child. On the other hand, it elicited more willingness to help implement learning assistance, medication and changes to the classroom environment.

A lot of international studies have showed evidence for the improvement of knowledge on ADHD by educational interventions. Workshops about ADHD, not-attendance education, and web-based interventions have shown to provide at least short-term effectiveness. It remains unclear if there is any long-term maintenance in the behavior of professionals because there are little to no follow-ups.

There seem to be differences in the way parents, teachers, children and health care professional view a shared decision-making process (SDM). Parents ought to think that it’s an equal partnership and want clinicians to provide them with information about all treatment options, while clinicians see it as a process of explaining their own views on treatment options and encourage parents to accept them by providing supporting information. These differences emphasize the need to negotiate a common understanding and shared goals in from the beginning of a SDM process.

Researchers concluded that adolescents with ADHD should be involved in the informed consent process, but consideration should be given to their cognitive abilities. It’s important to involve adolescents in their own treatment plan because it appears that their willingness to consider treatment is significantly lower than that of their teachers and parents.

A multidisciplinary approach to the diagnosis of ADHD is recommended by the guidelines, but often fails to be followed. Pediatricians often diagnose ADHD and subscribe medication without consulting a psychiatrist, while when psychiatrist diagnose ADHD they don’t communicate this with the pediatricians who have to refill prescriptions.

To identify the obstacles to treatment success, a tool has been developed that includes a medication preference scale, a goal scale and a behavior therapy preference scale which can be filled in by parents and children. Other tools are the Questionnaire on Attitudes Towards Treatment of ADHD and the ADHD Medication Attitude Scale. The latter has shown that treatment adherence is lower in adolescents.

Thus, there is a need for continued education of teachers, health care professionals and the public about ADHD, and especially about its etiology and treatment. These areas seem to provide the most misconceptions and reinforce stigma attached to ADHD.