Objective: Antidepressant switch is a commonly used strategy in the absence of an adequate response, but optimum timing is not well established. We compared the efficacy of an early and a conventional antidepressant switch strategy in patients with major depressive disorder.
Methods: Patients with no or minimal improvement (<30% reduction in baseline 17-item Hamilton Depression Rating Scale [HAMD17] score) after 4 weeks on escitalopram 10 mg/d were randomized to either early switch strategy with duloxetine 60 to 120 mg/d for 12 weeks (arm A) or conventional switch strategy (arm B): 4 further weeks on escitalopram 10 to 20 mg/d; then, in case of nonresponse (response, ≥50% reduction in HAMD17), switch to duloxetine 60 to 120 mg/d for 8 weeks, or continued escitalopram in responders. Co-primary end points were time to confirmed response and remission (HAMD17, ≤7). Strategies were compared using Kaplan-Meier, logistic regression, and repeated-measures analyses.
Results: Sixty-seven percent (566 of 840) of patients showed no or minimal improvement and were randomized to arm A (282 patients) or arm B (284 patients). No between-strategy differences in time to confirmed response (25% Kaplan-Meier estimates, 3.9 vs 4.0 weeks, P = 0.213) or remission (6.0 vs 7.9 weeks, P = 0.075) were found. Rates of confirmed responders were similar (64.9% vs 64.1%); however, more patients randomized to early switch achieved confirmed remission (43.3% vs 35.6%; P = 0.048).
Conclusions: Although no differences in the primary end points were found, a higher remission rate was seen with the early switch strategy. Our findings suggest that further investigations to reevaluate the conventional approach to antidepressant switch strategy would be worthwhile.