UCLA

Dual diagnosis of autism spectrum disorder (ASD) and behavior problems and/or mental disorders has become increasingly recognized and studied. Reported rates in samples of mixed-age youth with ASD are often above 70%, making this comorbidity more the rule than the exception. The present study compared rates of disruptive behavior disorder diagnosis in a sample of 13-year-old adolescents with ASD (n = 58), intellectual disability (ID; n = 40), or typical cognitive development (TD; n = 100). In youth without ASD, there was a high negative correlation between IQ and disruptive behavior disorders, assessed with the Child Behavior Checklist (CBCL) and the Diagnostic Interview Schedule for Children (DISC). In youth with ASD, however, the presence of a comorbid disruptive behavior disorder was unrelated to IQ, indicating that higher intelligence was not a protective factor for disruptive behavior disorders (DBDs) in ASD. On four CBCL scales and two DISC scales examined, youth with ASD had significantly higher rates than TD youth, though not generally higher than youth with ID. The most commonly diagnosed comorbid disorder in the early adolescents with ASD was attention-deficit/hyperactivity disorder. This has implications for planning school-based interventions, particularly for high-functioning children with ASD who are more likely to be fully included in general education.