IACAPAP e-Textbook of Child and Adolescent Mental Health.
J. M. Rey (2018)
Chapter F.1
Anxiety disorders in children and adolescents: Nature, development, treatment and prevention.

Introduction

In the child and adolescent fields, there is a more common tendency to examine disorders as a whole.

Externalizing disorders are disorders in which people act out inner conflict or emotions. Internalizing disorders reflect problems with the self.

Description and diagnosis

The core feature of anxiety disorders is avoidance. In most cases, this includes overt avoidance of specific situations, places or stimuli. It may also involve subtle forms of avoidance such as hesitancy, uncertainty, withdrawal, or ritualized actions. The key difference between specific disorders is the trigger for this avoidance. The avoidance is generally accompanied by affective components of fearfulness, distress or shyness. Some children may have difficulty verbalising these emotions.

Anxiousness occurs due to an expectation that some dangerous or negative event is about to occur. In identifying the anxious child, it is crucial to determine that the avoidance occurs due to an expectation of some form of threat. All of the anxiety disorders will involve an anticipation of threat, which may take the form of worry, rumination, anxious anticipation, or negative thoughts. The key differences between disorders lie in the content of these beliefs. In addition to the beliefs, behaviours and emotions, anxious children will often report a range of associated physical complains reflecting heightened arousal. These are rarely specific to a given disorder.

Physical symptoms that are common among anxious children include: Headaches, stomach aches, nausea, vomiting, diarrhoea, and muscle tension. It is common for many anxious children to have difficulty with sleep.

Anxiety-related disorders

Children with obsessive compulsive disorder (OCD) report repetitive and intrusive thoughts, images or urges, often accompanied by repeated characteristic actions or behaviours with the goal of reducing anxiety. The mental components commonly focus on some expected threat or danger, although sufferers from some forms of OCD might focus more one a sense of disgust and a belief that certain actions simply ‘feel right’. When a threat expectation exists, the corresponding rituals are generally aimed at preventing or undoing the expected danger.

Many children are unable to clearly describe their beliefs and motivations.

Post-traumatic stress disorder involves a constellation of symptoms of heightened arousal, intrusions, detachment, and avoidance that occur following a severe event. Post-traumatic stress disorder is relatively infrequent in childhood.

School refusal

School refusal is not a formal diagnosis.

School refusal is not an anxiety disorder and may be motivated by many factors aside from anxiety. When it occurs, anxiety is a common underlying element. But, anxiety alone is not a sufficient explanation. School refusal involves both a motivation from the child not to attend school (sometimes due to anxiety) combined with a social and, usually, parental acquiescence to this demand.

School refusal commonly involves some difficulty within the family or at least one parent.

Chronic school refusal may reflect a variety of anxiety (or other) difficulties within the child combined with parental or family difficulties and in some cases with social support for nonattendance.

Comorbidity

There is a strong overlap between the various anxiety disorders and between anxiety and other internalising disorders, especially depression. Clinically anxious children rarely meet criteria for only one disorder. An overlap between anxiety disorders and alcohol abuse begins to appear from late adolescence or early adulthood.

Epidemiology

Prevalence

Overall, around 5% of children and adolescents meet criteria for an anxiety disorder during a given period of time in Western populations. In most studies prevalence is highest for specific phobias and moderate for separation anxiety, generalized anxiety and social phobia.

Gender distribution

Anxiety disorders are more common in females than males in the general population. There is some evidence that this gender difference appears very early (5 years of age). Distributions of treatment-seeking samples in Western societies are more equal.

Age of onset

Anxiety disorders are among some of the earliest disorders to appear and most commonly begin by middle childhood to mid adolescence. It is common for anxiety disorders to occur within a context of temperamental inhibition and fearfulness.

Course

Anxiety disorders are the most stable forms of psychopathology and show relatively little spontaneous remission. Anxious children are at increased risk of developing other disorders during adolescence and into adulthood.

Other demographic features

Anxiety in childhood is characterised by very few demographic risk factors.

Assessment

Clinical evaluation generally includes a combination of questionnaires, diagnostic interview and behavioural observation. In most clinical settings, a diagnostic interview and a small number of questionnaires will be most appropriate.

Diagnostic interview

Most interviews include a large number of questions aimed to tap each of the relevant diagnostic criteria and generally differ in their degree of structure.

Some widely used instruments include 1) Kiddie schedule for affective disorders and schizophrenia (K-SADS) 2) Development of wellbeing assessment (DAWBA) 3) Diagnostic interview schedule for children (DISC)

If the interest in anxiety more specifically, then the anxiety disorders interview schedule for children (ADIS-C) has a primary focus on these disorders.

For very young children, the preschool age psychiatric assessment (PAPA) is a useful instrument.

In most disorders of childhood, information from parents and children about anxiety disorders commonly contains several discordant aspects. Clinical judgement and experience needs to be applied to determine which information is more heavily weighted and how best to combine the information. Anxious children are often thought to ‘fake good’. Many parents are also anxious and in some cases will exaggerate the child’s difficulties due to their own distress.

Clinically, distinguishing between specific disorders can be difficult. It is important to determine the basic motivation behind particular behaviours in order to identify the relevant diagnosis. Clinically, once all behaviours, motivations, and diagnostic criteria have been assessed it has been determined that a child meets criteria for two (or more) clearly distinct disorders, it is generally useful to determine which of the disorders is principal (primary). The principal disorder is the one that procedures the greatest impact and interference in the child’s life. This disorder is usually the initial focus in therapy.

In some cases, it may be more important to determine which disorders appears to be the underlying or causal problem. In other cases, a particular problem may be expected to interfere with treatment response and may therefore require initial attention, even if it is not the principal disorder.

Questionnaire assessment of child anxiety

The severity of anxiety or extent of anxiety symptomatology can be measured using several questionnaires.

A few questionnaires contain subscales that each tap diagnostic-like constructs. Most of these questionnaires have parallel versions for the parent and child. A similar measure has been developed for preschool-aged children, to be completed by their parents only.

Several other measures aim to assess the overall degree of anxiousness.

In some circumstances, more specific and detailed assessment of a particular form of anxiety may be required.

Risk and maintaining factors

Family transmission

Anxiety runs in families. First degree relatives of people with anxiety disorders are at increased risk to also have anxiety as well as mood disorders. Anxious children are considerably more likely to have parents with anxiety disorders. A similar relationship occurs more generally for temperament that is related to anxiety.

People with a particular disorder are more likely to have first degree relatives with that same disorder than other anxiety disorders.

Family transmission can reflect both genetic and environmental influences, so it is tempting to speculate that genetic transmission confers a broad, general risk, while family environment may shape that risk into specific manifestations.

Genetic factors

Anxiety disorders are heritable. Genetic risk across anxiety disorders appears to be largely general and seems to primarily load on a very broad factor.

No evidence exists linking any individual gene specifically to anxiety.

Temperamental factors

A variety of similar temperaments have been associated with child anxiety. Together, these factors are inhibition. These factors are: behavioural inhibition, withdrawal, shyness, and fearfulness. Children who show these characteristics during preschool age are two to four times more likely to meet criteria for anxiety disorders by middle childhood and this risk continues into adolescence.

The main complication with this research is the extensive overlap between the constructs of inhibition and anxiety disorders.

Parent and family factors

The parenting of anxious children is characterised by overprotection, intrusiveness and negativity. It is not known if this is causal. Parent-child relationship is likely to reflect cyclical interactions.

Another theory is that anxious parents increase risk for anxiety in their children by modelling their own fears and coping strategies. This theory has received little examination.

Sexual abuse, and to a lesser extent physical abuse and family violence, can increase anxiousness in children. This increase is likely to be temporary and it is not clear whether these factors contribute significantly to the development of longer-term anxiety disorders. These factors are relatively non-specific and increase risk for a wide variety of child psychopathology.

Live events

Anxious children report a greater number and impact of negative life events. But this does not mean that these events necessarily cause or trigger anxiety.

Cognitive biases

Anxious children report heightened beliefs and expectation of threat. So some extent the threat expectancies are specific.

Anxious children have a bias in attention toward threat and a bias to interpret ambiguous information in a threat-consistent manner.