Sertraline versus imipramine to prevent relapse in chronic depression

Background: Chronic depressions are common, disabling and under-treated, an d long-term treatment is little studied. We report the continuation phase r esults from a long-term treatment study. Methods. After 12 weeks of acute p hase treatment in a double-blind, randomized, parallel-group, multi-center trial of sertraline or imipramine. patients with chronic depression ( great er than or equal to 2 years in major depression, or major depression superi mposed on dysthymia) continued study drug for 16 weeks. Initially. 635 pati ents were randomized to sertraline or imipramine in a 2:1 ratio. Nonrespond ers after 12 weeks entered a 12-week double-blind crossover trial of the al ternate medication. Entry into continuation treatment required at least a s atisfactory response (partial remission) to initial or crossover treatment. Results: Of 239 acute or crossover responders to sertraline. 60% entered c ontinuation in full remission and 40% with a partial remission. These propo rtions were identical for imipramine patients (n = 147). For both drug grou ps, over two-thirds of those entering in full remission retained it. For th ose entering in partial remission, over 40% achieved full remission. patien ts requiring crossover treatment were less likely to maintain or improve th eir response during continuation treatment. The two drugs did not differ si gnificantly in response distribution, drop out rates or discontinuation due to side effects during continuation treatment. Limitations: The absence of a placebo group constrains interpretation of our results, but chronic depr essions have low placebo response rates. Conclusions: Most chronic depressi on patients who remit with 12 weeks of sertraline or imipramine treatment m aintain remission during 16 weeks of continuation treatment. Most patients with a satisfactory therapeutic response (partial remission) after 12 weeks of treatment maintain it or further improve. Patients treated with imipram ine experienced more side effects. but both drugs were well tolerated. (C) 2001 Elsevier Science B.V. All rights reserved.