Comparison of mirtazapine and fluoxetine in the treatment of major depressive disorder: a double-blind, randomized trial

Background: Depression is an international public health problem. The aim of this study was to compare the efficacy and tolerability of mirtazapine and fluoxetine treatment in a sample population consisting of Iranian patients suffering major depressive disorder. Methods: Thirty-six inpatients and outpatients with a diagnosis of major depressive disorder (Diagnostic and Statistical Manual of Mental Disorders-IV) and a score >= 18 on the 17-item Hamilton Rating Scale for Depression (HAM-D-17) were randomly assigned to 6 weeks of treatment with mirtazapine (30 mg/day) or fluoxetine (20 mg/day). Efficacy was assessed by HAM-D-17. Information about adverse events was obtained by questioning of participants and/or their examination. Assessments were performed at weeks 0, 1, 2, 3, 4 and 6. Results: Sixteen of mirtazapine-treated patients and fifteen of fluoxetine-treated patients completed the 6-week study period. Both treatment groups were well matched at baseline with respect to demographic and disease characteristics. Both drugs showed a significant improvement over the 6 weeks of treatment (P < 0.001). There was no statistically significant difference between the mean +/- SEM HAM-D scores of two groups at weeks 1, 2, 3, 4, and at the end point. There were no significant differences between two groups in terms of response to treatment (>= 50% decrease from baseline in HAM-D-17 total score) and remission (HAM-D-17 score of <= 7). None of the differences in reported adverse events was statistically significant. Conclusion: In this study, mirtazapine and fluoxetine were equally effective and well tolerated after 6 weeks of treatment in patients with major depressive disorder.