Bupropion sustained-release for the treatment of dysthymic disorder: an open-label study.

Many studies of antidepressants in the treatment of dysthymic disorder (DD) have been conducted, but none has included bupropion sustained-release (SR). The aim of this study was to provide preliminary data on the tolerability and effectiveness of bupropion SR for patients with DD. Twenty-one adult subjects meeting DSM-IV criteria for DD were enrolled in this 8-week open-label study. Bupropion SR was initiated at 150 mg/day and was increased to a maximum of 200 mg, twice daily. Response was defined as a 50% or greater decrease in score on the Hamilton Rating Scale for Depression (HAM-D). Of these 21 subjects, 15 (71.4%) responded to treatment. All paired sample t-tests were highly significant, demonstrating average improvement on all measures of symptomatology and functioning. Subject scores on the HAM-D decreased from 21.7 +/- 5.6 at baseline to 5.9 +/- 3.6 at week 8 (t[19] = 12.74, p < 0.001). The average final dosage was 364 mg/day. None of the subjects dropped out during the trial. Patients with a history of alcohol or chemical abuse were significantly less likely to respond to bupropion. Side effects were reported by eight subjects (38.1%), and the most frequently reported effects were headache, decreased appetite, insomnia, gastrointestinal problems, restlessness, and tremulousness. These findings suggest the effectiveness and high tolerability of bupropion SR for the treatment of DD. Double-blind prospective studies are needed for the comparison of bupropion SR to both placebo and other medications, assessing both initial and sustained responses to treatment.