An Open-Label Rater-Blinded Randomized Trial of Vilazodone versus Escitalopram in Major Depression

Background: Vilazodone, a novel selective serotonin reuptake inhibitor and 5-HT1A partial agonist, was approved in 2011 for treatment for major depression. We aimed to compare the efficacy and safety of vilazodone versus escitalopram in patients with major depression at 4 weeks.

Methods: Participants (n = 52) were adult major depressive disorder outpatients who were randomized to receive either oral escitalopram (modal endpoint dose 20 mg/day; n = 26) or oral vilazodone (modal endpoint dose 40 mg/day; n = 26). Rater-blinded assessments of depression scores (primary outcome) and clinical severity of illness (secondary outcome) were obtained at baseline, 2 weeks, and 4 weeks. Adverse effects such as weight gain, sexual dysfunction, and diarrhea were recorded at each visit. The primary analysis was performed on the Intention-to-treat sample.

Results: No significant difference was noted between groups on depression scores at study endpoint (F = 2.80, df = 1,50, P = 0.10); however, the vilazodone group had significantly lower endpoint clinical severity of illness (F = 7.69, df = 1,50, P = 0.01). At 2 weeks, there were no significant between-group differences on depression scores (F = 0.006, df = 1,50, P = 0.94). Instances of diarrhea (P = 0.001) were significantly higher in the vilazodone group.

Conclusion: Clinical ratings of major depression did not differ significantly between vilazodone and escitalopram groups at the end of 4 weeks. Our findings are limited by lack of statistical power to detect smaller differences between groups, should they exist.