A randomized, single-blind comparison of duloxetine with bupropion in the treatment of SSRI-resistant major depression

INTRODUCTION: For patients who continue to experience depressive symptoms despite an adequate antidepressant SSRI trial, across-class switch is considered one of the best treatment options. The goal of the present work was to compare in terms of efficacy two different dual-action compounds, duloxetine and bupropion, in patients who failed to respond in two consecutive antidepressant trials with SSRIs. METHODS: The patients were allocated randomly to duloxetine (120 mg daily) or bupropion extended release (300 mg daily). The intended medication period was 6 weeks. The primary measure of efficacy was depressive symptoms severity. RESULTS: A total of 49 participants were randomly assigned to duloxetine 120 mg (n=27) or bupropion 300 mg (n=22). The ITT efficacy patient sample consisted of 46 patients. Relatively high response and remission rates in treatment groups were found: from 60 to 70% of patients responded to treatment, and approximately 30 to 40% were in remission by the endpoint (week 6). No statistically significant difference emerged between the two groups at any post-baseline assessment, neither on mean scores of rating scales nor on qualitative efficacy measures. LIMITS: Limitations of the study are the lack of a placebo arm, difficult to include owing to ethical reasons, and the relatively small size of the sample. CONCLUSIONS: These preliminary results seem to support the hypothesis that in patients unresponsive to SSRIs the administration of antidepressants with different mechanisms of action is an effective switching strategy. Further studies are needed in light of the challenge posed by resistant depression.