--- - |2+ Background 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. Methods Two hundred and forty‐nine children with ADHD and their parents completed follow‐up questionnaires around 5 years after taking part in a Cardiff University ADHD study. Child depression symptoms were measured using parent‐ and child‐reported Mood and Feelings Questionnaires (MFQ) and compared to a population sample with MFQ data (n = 1460). Within both samples, child‐ and parent‐reported depression symptoms were compared. Results Although the profile of depression symptoms was similar between young people with ADHD and those in the general population, depression symptoms were much more common in the ADHD sample (parent‐rated MFQ score = 24.52 vs. 9.39; child‐rated = 21.02 vs. 11.86). The most common symptoms in both samples included irritability, restlessness and concentration difficulties, with core depression symptoms such as feeling miserable/unhappy also prominent. Within the ADHD sample, but not the population sample, children reported depression symptoms less frequently than their parents. Conclusions Young people with ADHD are at high risk of experiencing symptoms of depression but may under‐report the severity of their symptoms. Obtaining parent reports of depression symptoms in this group may be important to avoid missing key indicators of risk. - Child and Adolescent Mental Health, Volume 23, Issue 3, Page 243-250, September 2018.