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…

It is generally accepted that Attention-Deficit/Hyperactivity Disorder (ADHD) results from a dysfunction of the central nervous system, which has led to a commonly held belief that environmental factors play little role in the behavioural problems of children identified as having ADHD. Therefore, the two studies reported in this article…