Academic underachievement and the disruptive behavior disorders.

Academic underachievement (AU) was studied among 177 clinic-referred boys reliably diagnosed as having attention-deficit hyperactivity disorder (ADHD) or conduct disorder (CD). Unlike previous studies, the present study assessed AU using a formula that determined the discrepancy between a child's predicted level of achievement and actual level of achievement while controlling for regression and age effects. AU was associated with both ADHD and CD when the disorders were examined individually. However, when examined in multivariate logit model analyses, the apparent relation between CD and AU was found to be due to its comorbidity with ADHD. When boys with ADHD were divided into those with attention deficits only and those with co-occurring hyperactivity, findings did not support the hypothesis that the association with AU is stronger for attention deficits without co-occurring hyperactivity.