Development of Depression During Placebo-Controlled Trials of Bupropion for Smoking Cessation: Case Reports

Background: Recent attention has focused on the relationship between depression and smoking cessation. This article describes 5 cases of severe depression that occurred during 2 multicenter trials using bupropion for smoking cessation.

Method: Subjects were participants in 2 randomized, double-blind, placebo-controlled studies investigating the efficacy of bupropion for smoking cessation. Data from both trials were restricted to subjects at the Rochester, Minn., site in order to have access to the medical records for information on depression diagnosis, treatment, and follow-up. The first trial involved 205 smokers who received active bupropion or placebo for 7 weeks. In the second trial, 252 smokers received open-label bupropion therapy for 7 weeks. Those abstinent from smoking at the end of week 7 (N = 148) were randomly assigned to a 45-week, double-blind, relapse-prevention phase.

Results: In the first trial, 1 of the 205 participants (0.49%) experienced major depression during the 7-week treatment phase. In the second trial, none of the 252 subjects developed major depression during the 7-week, open-label phase. When results of both trials across the 7-week treatment phase (study 1, N = 205; study 2, N = 252) are combined, the rate of developing major depression was 0.22% (1 of 457). Of the 457 subjects, none of the 51 who received placebo and 1 (0.25%) of the 406 who received active bupropion developed major depression. In the second trial, 4 (2.7%) of the 148 subjects randomly assigned to the 45-week, relapse-prevention phase developed depression. Overall, 4 of the 5 cases from the 2 trials had a past history of major depression prior to study entry, but none had current major depression.

Conclusion: Major depression may occur in some individuals during smoking cessation treatment with bupropion.