Depression, suicidal ideation and self-harm are common in adolescents; however, such difficulties often remain undetected. The aim of this study is to combine a school-based depression education program with a case-detection system in order to improve the recognition of depression; increase help-seeking; reduce stigma; and identify people at risk. The study employed a pre-test, post-test design with a wait-list control group. Participants were 343 14- to 16-year-old boys attending an Australian secondary school. The intervention comprised a one-off, 2-h workshop. Participants were assessed via questionnaire at three time points; the case-detection tool was embedded in the questionnaire. Participation led to an increased likelihood of seeking help; an increased likelihood of rating a relevant professional as helpful and improved attitudes. The screening led to the detection of 20 at-risk students. The program led to short-term improvements in mental health literacy and to the identification of several at-risk students.