To determine whether elderly (60-80 years old) depressed patients who cannot sustain a remission without medication must be maintained at full acute-treatment dose. To compare the efficacy of full-dose vs half-dose nortriptyline (NT) in preventing recurrences of major depression in the elderly. To determine whether those patients who experience a recurrence while in a maintenance placebo condition (Study I) require 100 percent of their acute-treatment dose of NT to prevent subsequent recurrences or can be successfully maintained on 50 percent of their acute-treatment dose (Study II).

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.