Introduction

People with an autism spectrum disorder often experience difficulties in social behavior and communication. Often they also engage in repetitive behavior. Seventy percent of the population with ASD also experience other psychiatric disorders such as social anxiety and oppositional defiant disorder. Over time, there is a growing interest in the role of emotion control as a mediator for internalizing and externalizing behavior in these adolescents. Emotion control could be the underlying mechanism for these problems, because emotion control is very important in life. When someone is able to control his or her own emotions, it may help to keep an optimal level of arousal which is needed to achieve social and personal goals. Emotion control takes time to develop, and its development is partly dependent on social experiences and it is also modeled through social learning. People often learn from childhood on to control their emotions in a socially and culturally accepted way. Children with an autism spectrum disorder, however, often have less access to these social environments and they also show more deficits in their ability to control their emotions.

This study examines three indices which are related to emotion control: negative emotionality, emotion awareness and worry or rumination and their relationship to the development of internalizing and externalizing behavior problems in children and adolescents with autism spectrum disorder. These children and adolescents are compared to typically developing youth, so a control group.

Emotion control is the term that is used to describe several aspects of the ability to down-regulate emotions in emotion-evoking situations. When people experience problems with emotion control, these problems could be related to emotion generation and/or to the process of dealing with emotions. The different indices of emotion regulation are related to internalizing and externalizing behavior. One of the indices of emotion control is: frequently experiencing negative emotions, such as anxiety, fear and anger. This experience of negative emotions is a consequence of an inability to down regulate emotional over-arousal. Higher levels of negative emotions are associated with both internalizing and externalizing behavior problems in typically developing youth and in children and adolescents with autism spectrum disorders.

Emotion awareness is another indication of emotion control. Emotion awareness is the term for the ability to know how you feel and to link this feeling to an emotion-evoking situation. This awareness of emotions is essential for emotion regulation. A consequence of not being able to differentiate between emotions and focusing too much on bodily symptoms of an emotional experience is related to more depressive symptoms, anxiety symptoms and somatic complaints in typically developing children and children with autism spectrum disorders. Studies have also shown a relation between alexithymia (difficulties in describing and differentiating between emotions) and emotional problems in children and adolescents with autism spectrum disorder. 

The last described index of emotion control is worry or rumination. Worry and rumination are highly related processes which have to do with a chain of repetitive negative thinking. This repetitive negative thinking increases emotional over-arousal. The role of worry and rumination in youth with autism spectrum disorders has not been studied very often. This is strange, because it are especially youth with autism spectrum disorder who have a tendency to perseverate on things and therefore may be more susceptible to engage in worry and rumination. Worry and rumination is associated with developing internalizing behavior in typically developing youth. Earlier studies have shown a relationship between worry and rumination and depressive symptoms in children and adolescents with autism spectrum disorders. It has also been shown that worry and rumination are related to aggressive behavior in typically developing boys. However, it is unknown whether worry and rumination lead to disruptive behavior problems in children and adolescents with autism spectrum disorders. 

The literature on the role of emotion control on the development of internalizing and externalizing behavior is based on cross-sectional research. However, to understand the relationship between emotion control and internalizing and externalizing problems, longitudinal studies are needed. These will tell if the relations hold over time. Therefore, the authors of this article conducted a longitudinal study to test the relationship between negative emotionality, emotion awareness and worry/rumination with internalizing and externalizing behavior problems in boys in the ages of 9 to 15 with and without autism spectrum disorders. The authors chose for this age range, because it is often in adolescence that social and emotional problems increase.

The authors investigated three clusters of internalizing problems: depression, anxiety and somatic complaints. They investigated one general cluster of externalizing problems: disruptive behavior. 

The participants and their parents in this study filled in a questionnaire about different parts of emotion regulation and overall well-being at three time points, with an interval of 9 months. 

The aim of this study was: to test whether emotion control contributes to the prediction of internalizing and externalizing behavioral problems 18 months later; to examine the developmental trajectory of internalizing and externalizing behavioral problems over time; to test the co-occurrence of the developmental trajectory of emotion control with the developmental trajectory of internalizing and externalizing behavioral problems.

The expectations or hypotheses in these study were: negative emotionality, poor emotion awareness and worry/rumination are related to more internalizing problems in both boys with and without autism spectrum disorders; negative emotionality and worry and rumination will have a positive predictive value for externalizing behavior in both groups. 

Because of the fact that social environments can help to learn the skills related to emotion control and the knowledge that children and adolescents with autism spectrum disorder often are not in these environments, the authors of this article also expected that the relation between emotion control with internalizing and externalizing behavior will be stronger for boys with autism spectrum disorder compared to their typically developing peers.

Measurements

IQ

The authors used two nonverbal subtests from the Wechsler Intelligence Scale for Children-Third edition (WISC III) to calculate a general measure of intelligence. These subtests were not administered to two of the boys with autism spectrum and five typically developing boys because of time constraints.

Predictors

Negative emotionality

To assess the participants negative mood over the past four weeks, the authors used a self-report questionnaire. They used three subscales of the mood list: anger, fear and sadness. Each subscale consists of four items. The higher the score, the more negative and dysregulated the emotional experience.

Emotion awareness

Two subscales of the Emotion Awareness Questionnaire were used to differentiate between emotions and bodily awareness of emotions. The subscale for differentiating emotions consists of seven items and measured whether the children were able to differentiate between their own emotions. An example of such an item is: "I am often confused or puzzled about what I am feeling". A high score indicates a good ability to differentiate between emotions. The subscale "Bodily Awareness of Emotions" measures whether children are aware of bodily changes that are related to their emotions. This consists of five items. An example of an item is: "I don't feel anything in my body when I am scared or nervous". A high score indicates low bodily awareness.

Worry and rumination

To assess the tendency of children to dwell on a problem instead of dealing with it (by means of solving the problem or coping adaptively), the worry and rumination questionnaire for children is used. This is a self-report measure. It consists of ten items and an example of an item is: "When I have a problem, I think about it all the time". The higher the score, the higher the level of worry and rumination.

Outcome Measures

Disruptive Behavior Problem

The Child Symptom Inventory is a behavior rating-scale to assess childhood disorders. It is based on DSM-IV criteria. In this study, there was looked at whether there were problems related to attention deficit hyperactivity disorder (ADHD), oppositinal deviant disorder (ODD) and conduct disorder (CD). There were seventeen items to measure ADHD ("Is quickly distracted"), eight items to measure symptoms of ODD ("Does things to deliberately annoy others"), and fifteen items to assess symptoms of CD ("Has deliberately started fires"). The parents were asked to rate each item on a four-point scale. A higher score indicates more disruptive behavior. So, these were the measures for externalizing behavior.

For internalizing behavior, there was looked at anxiety, depression and somatic complaints.

Anxiety

The Child Symptom Inventory was also used to assess problems related to generalized anxiety. Parents rated their children's generalized anxiety symptoms in the last six months on seven items. A higher score means more anxious feelings.

Depression

To measure symptoms of depression, an adapted Dutch version of the Children's Depression Inventory (CDI) was used. This is a self-report questionnaire which includes twenty-seven items. An example of an item is: "I am sad". The higher the score, the higher the depressive mood. 

Somatic complaints

Somatic complaints were measured using the Somatic Complaint List (SCL). Children reported the frequency in which they experienced certain somatic complaints such as a headache in the past four weeks. The higher the score, the more somatic complaints.

Discussion

Many children and adolescents with autism spectrum disorder show additional emotional and behavioral problems, next to the core symptoms of their disorder. Therefore, it is important to look at the underlying mechanisms to explain this co-occurence of symptomatology. This will help in developing effective tools for prevention and interventions. In this study, three indices of emotion control that are thought to play a key role in the development of additional problems in children and adolescents with autism spectrum disorder, were examined. The main findings are: baseline levels of worry and rumination are a risk factor for developing externalizing behavior symptoms 18 months later, but only for boys with autism spectrum disorder; the developmental trajectory of internalizing and externalizing behavior symptoms did not differ between boys with and without autism spectrum disorder; increase in worry and rumination over time was related to the development of more externalizing behavior problems in boys with and without autism spectrum disorders; increase in worry and rumination and increase in negative emotionality contributed both to the development of more internalizing behavior symptoms in boy with and without autism spectrum disorders, but the relationship between worry and rumination and somatic complaints was only there for boys with autism spectrum disorders.

Developmental Trajectory of Internalizing and Externalizing Behavior in Both Groups

So, in line with previous research, the authors found that boys with autism spectrum disorder showed more internalizing and externalizing behavior problems compared to boys without autism spectrum disorders. But, the speed of development of these symptoms did not differ between the groups. Also, there was no increase in symptoms of depression and generalized anxiety found. 

The findigs also showed that there is a decrease in externalizing behavior with age for boys with and without autism spectrum disorders. This is in line with previous studies which showed that there is a negative relationship between agressive behavior and age. 

Because it is known that adolescence is a time period which is characterized by big changes in behavior and biology, the authors also looked at whether this period is an additional risk factor for boys with autism spectrum disorders. This does not seem to be the case. It seems that the heightened sensitivity that these boys show, are already evident during their childhood. And, because children with autism spectrum disorders are less able to participate in social life, this probably affects their opportunity to practice and achieve emotion control. This may explain why these symptoms emerge prior to adolescence.

Worry and Rumination as a Risk Factor for Developing Externalizing Symptomatology

This study showed that boys with autism spectrum disorders exhibit more disruptive and aggressive behavior compared to boys without autism spectrum disorders. This might be, because they experience more frustration and negative thoughts. This study showed that baseline levels of worry and rumination are indeed a risk factor for disruptive behavior eighteen months later, but only for boys with autism spectrum disorders. It is also possible that not only worrying and ruminating lead to more disruptive behavior; it may also be the case that the content of the worry and rumination differs between children with autism spectrum disorders and typically developing children. For example, high-functioning individuals with an autism spectrum disorder are often well aware of their (social) difficulties. This may be an important source for daily problems and worries, especially during adolescence, because this is a time period in which peers are important in daily life. Findings showed that adolescents with autism spectrum disorders indeed report more anger rumination compared to typically developing youth. But, it does not seem to be the case that boys with autism spectrum disorders ruminate more than boys without an autism spectrum disorder.

Emotion Control as a Risk Factor for Developing Internalizing Symptomatology

Boys with autism spectrum disorders show a higher sensitivity to develop internalizing behavior symptoms. This study shows that thinking repeatedly and negatively about daily problems increases the risk for developing internalizing behavior problems 18 months later in boys with and without autism spectrum disorders. Also, an increase in the frequency of worry and rumination also increase internalizing symptoms. So, it seems that worry and rumination and externalizing behavior symptoms are a transdiagnostic factor that underlies multiple types of psychopathology.

Regularly experiencing negative emotions also is an risk factor for internalizing problems. For example, boys with and without autism spectrum disorders who have negative emotionality, have more internalizing symptoms (anxiety, somatic complaints) eighteen months later.