This practice parameter describes the epidemiology, clinical picture, differential diagnosis, course, risk factors, and pharmacological and psychotherapy treatments of children and adolescents with major depressive or dysthymic disorders. Side effects of the antidepressants, particularly the risk of suicidal ideation and behaviors are discussed. Recommendations regarding the assessment and the acute, continuation, and maintenance treatment of these disorders are based on the existent scientific evidence as well as the current clinical practice.