The study also tested the hypothesis that children with ADHD may have increased prevalence of snoring and OSAS. Children with this diagnosis were initially confirmed as having ADHD using the revised Diagnostic Interview for Children and Adolescents, the Conners' Parent Rating Scale, and the Child Behavior Checklist. ADHD children then underwent polysomnographic evaluation as well as extensive evaluation of neurocognitive function and behavior as above. The prevalence of snoring and OSAS were then calculated.