Depression is a common, potentially devastating comorbidity in youth with attention-deficit/hyperactivity disorders (ADHD). Various environmental adversities are well-described as correlates of depression in general pediatric populations, but not in youth with ADHD. In 104 adolescents with ADHD, we examined potential environmental correlates of lifetime depression, including trauma exposure, recent negative life events and current parent-child conflict, along with current and past ADHD severity and current impairment. Controlling for demographic variables, comorbid disorders, and ADHD severity, we noted significant associations between lifetime depression and environmental adversities, including victimization trauma, parent-child conflict, and behaviorally-independent negative life events. Current impairment but not ADHD severity was also highly associated with lifetime depression, controlling for the same covariates. Findings from this preliminary, cross-sectional study suggest that environmental adversities and impairment in youth with ADHD should also be targeted along with the ADHD when contemplating strategies to treat or prevent comorbid depression.