Investigators expect a pool of 60 patients from Study I to become eligible for Study II (the full-dose/half-dose maintenance trial). After treatment of the recurrence and following 16 weeks of stabilization therapy, patients are randomized to 1 of 2 maintenance therapy cells: full-dose NT or half-dose NT. Maintenance lasts 2 years or until recurrence of major depression. The following are assessed: differences in recurrence rates and time to recurrence under full-dose vs half-dose conditions; differences in symptomatic ratings of depression, suicidal ideation, social adjustment, and side effects; and differences in compliance rates as determined by variability in level-to-dose (L/D) ratios. Exploratory data analyses are used to generate a hypothetical profile of elderly patients who can remain well on half-dose maintenance nortriptyline.