All participants in this study will first be treated with imipramine for 7 to 11 months. Once remission of depression symptoms has been achieved and maintained for 20 weeks, participants will be randomly assigned to one of the following five maintenance treatments for 36 months: psychotherapy plus imipramine; psychotherapy plus placebo; psychotherapy alone; medication clinic treatment plus imipramine; or medication clinic treatment plus placebo. Assessments will be made at Weeks 12 and 20 and Months 7, 11, and 36, and will include the time it takes for depression symptoms to recur, as well as scores on depression and mania severity scales.