Selective serotonin reuptake inhibitors may be less efficacious than tricyclic antidepressants in the treatment of severe depression in older patients. The authors compared the 12-week clinical outcome of older depressed patients treated with nortriptyline or paroxetine in a double-blind randomized comparison in 116 psychiatric inpatients and outpatients (mean age: 72+/-8 years) who presented with a major depressive episode or melancholic depression. Discontinuation and response rates were compared in patients who began or who completed treatment. The discontinuation rate due to side effects was significantly higher with nortriptyline than with paroxetine (33% vs. 16%). There were no significant differences between the rates of response in the Intent-to-Treat analysis (nortriptyline: 57% vs. paroxetine: 55% ), or the Completer analysis (nortriptyline: 78% vs. paroxetine: 84%). Although paroxetine appears to be better tolerated than nortriptyline, the efficacy of these two drugs does not appear to differ in the acute treatment of older depressed patients, including hospitalized patients and those with melancholic features.