Open access. Attention-deficit/hyperactivity disorder (ADHD) frequently co-occurs with depression, and outcomes are poor when both are present. Little is known about whether depression symptoms present differently in ADHD compared to the general population, or how reliable young people with ADHD are at reporting these symptoms. This study aimed to describe depression symptoms in a clinical ADHD sample compared to a population sample, and compare self-reports of depression symptoms with parent-reports.