Although recent epidemiologic studies have established that patients with chronic medical illness and depressed mood are more disabled than euthymic patients, detailed data on the benefits and risks of antidepressant treatment in medically high-risk patients have been slow to accumulate. The authors have examined multiple outcome indicators in patients with disabling chronic obstructive pulmonary disease and comorbid depression. Thirty patients completed a 12-week, randomized controlled trial of nortriptyline. Nortriptyline was clearly superior to placebo for treatment of depression. Nortriptyline treatment was accompanied by marked improvements in anxiety, certain respiratory symptoms, overall physical comfort, and day-to-day function; placebo effects were negligible. Physiological measures reflecting pulmonary insufficiency were generally unaffected by treatment. These data provide impetus for renewed efforts to improve recognition and treatment of mood disorders in even severely disabled medical patients.