Depressive disorders are associated with significant psychosocial impairment and disability. Depression should be thoroughly evaluated, as should current and past suicidality and potential risk factors for suicide. Mortality by suicide characterizes the course of major affective disorders in approximately 15% of those suffering from these illnesses. Several neurobiological correlates of suicidality have been discovered. Treatment of depression with suicidality may involve hospitalization, pharmacotherapy, electroconvulsive therapy, and psychotherapy. Special populations include children and adolescents, the elderly, medically ill patients, patients with comorbid personality disorders, and patients with comorbid substance abuse disorders. Clinicians encountering patients with depressive disorders should be proficient in the assessment and treatment of depression with suicidality.