Major depression is a common mental health disorder in adolescents that predicts a significant risk for recurrence in adulthood. Suicide is the third most frequent cause of deaths in this age group, and depression is a significant risk factor for suicidal ideation and attempts. Risks for depression and suicidal ideation are reviewed, and subtypes of depression are discussed. Difficulties associated with identification of depression and suicidal ideation in adolescents and biologic therapies for adolescent depression are reviewed.