Intellectual Disability Modifies Gender Effects on Disruptive Behaviors

In typically developing children, boys are more commonly diagnosed than girls with disruptive behavior disorders, namely, attention-deficit/hyperactivity disorder, conduct disorder, and oppositional defiant disorder. For children with intellectual disability (ID), the evidence for this gender effect is less clear. In this report we examine gender effects on disruptive behavior in the Australian Child to Adult Development Study, a cohort of children and adolescents with ID, assessed in 4 waves. Items from the Developmental Behaviour Checklist were selected for their similarity to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association, 1994) criteria and their frequency compared for boys and girls after taking age and severity of ID into account, both individually and as a composite score. On 14 items, there were no significant gender differences. On 3 items, boys had significantly higher scores than girls, whereas for 1 item, girls scored higher. The extent of these differences was smaller than that reported in typically developing children. On a composite scale of all items, there was no significant effect of gender. We discuss possible explanations for the lesser effect of gender in children with ID.