23675
ADHD Severity As It Relates to Comorbid Psychiatric Symptomatology in Children with ASD
A growing body of research suggests that the prevalence rate of psychiatric comorbidity in individuals with ASD is much higher than it is in in the general population. Additional evidence suggests that ADHD contributes additional impairments in functioning. Not enough is known about the impact of ADHD on the development of comorbid psychiatric syndromes, or whether children with ASD who have more severe symptoms of ADHD are at higher risk for comorbid psychiatric symptomatology than are children with ASD who have milder ADHD symptoms.
Objectives:
The objectives of this study were to: 1) examine the rate of comorbid psychiatric disorders--including disruptive behavior disorders, mood disorders, anxiety disorders, elimination disorders, and eating disorders in children with ASD; and 2) determine if higher severity of ADHD symptomatology in children with ASD was associated with higher levels of psychiatric comorbidities and syndrome severity. It was hypothesized that children with ASD who have higher levels of ADHD symptom severity would be at higher risk for comorbid psychiatric diagnoses and symptomatology.
Methods:
Participants were 99 children (78 boys; mean age=9.4 yrs.; mean SB5 Full Scale IQ=84) who met DSM-IV criteria for ASD on the ADI-R and the ADOS. Analysis of ADHD severity (as assessed by Conners’ Rating Scale-Revised; Parent Version; global index) as a predictor of the number of comorbid diagnoses (using Diagnostic Interview for Children and Adolescents-Fourth Edition; DICA-IV) were examined using multiple regression analyses, with mental age (SB-5 FSIQ age equivalent) as a covariate. A regression model was then used to analyze the effect of ADHD severity on Child Behavior Check List (CBCL) symptom severity using eight subscale T scores as dependent variables (anxious/depressed, withdrawn, somatic complaints, social problems, thought problems, attention problems, rule breaking behavior, and aggressive behavior), with mental age as a control.
Results:
More severe ADHD symptomatology was associated with having more comorbid psychiatric diagnoses on the DICA-IV, F(1,95)=9.04, p= 0.003. More severe ADHD severity was also associated with higher levels of symptom severity on CBCL syndrome subscales, F(8, 88) = 23.56, p<0.001. Specific areas of concern included Disruptive Behavioral Disorders, Anxiety Disorders, Mood Disorders, Elimination Disorders, Eating Disorders, and Separation Anxiety Disorder. Interestingly, increasing severity of autistic symptomatology (as measured by ADI-R) was not associated with higher risk of comorbid psychiatric diagnoses or CBCL syndrome severity. These findings suggest that ADHD severity--but ASD severity--is associated with a higher risk for comorbid psychiatric symptomatology in children with ASD.
Conclusions:
These results suggest that children with ASD who also have severe ADHD symptoms are at high risk for a other psychiatric comorbidities. Not only did we find that a greater number of psychiatric diagnoses were associated with ADHD in children with ASD, but also that more severe ADHD symptoms led to more severe psychiatric symptoms in these children. It is interesting to note that ASD symptomatology was not associated with a higher risk for psychiatric comorbidity or severity. These results lend support to the notion that greater ADHD symptoms is a risk factor for greater comorbid psychiatric problems in children with ASD.