Treatment of depression is based on comprehensive diagnostic, clinical and psychosocial evaluation. Brief psychotherapies (cognitive, interpersonal, psychodynamic or problem-solving) are effective in mild to moderate depression; antidepressants in mild to severe, and electroconvulsive therapy in severe or psychotic. Combining antidepressants and psychotherapy is more effective than either alone. After the acute phase, antidepressants should be continued for six months to prevent relapses, and maintenance treatment considered after three lifetime episodes. Primary care is responsible for treatment of mild to moderate depressions; developing psychiatric consultation services and use of nurse case managers are recommended.