Risk of adverse events in treatment-resistant depression: propensity-score-matched comparison of antidepressant augment and switch strategies

Abstract

Objective: The objective was to assess differences in adverse events between major depressive patients augmented with a second medication and patients switched to an alternative monotherapy after failing first-step treatment with citalopram.

Method: Adverse event profiles for second-step switch and augment medication strategies were compared using public data files from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial. In the STAR*D trial, participants failing citalopram selected acceptable next-step strategies and were randomized within acceptable strategies. This design resulted in clinically important differences when comparing across strategies, so a propensity-score-matched sample was created to compare switch (n=269) and augment (n=269) strategies.

Results: Incidence proportions of any adverse event and specific adverse events were similar between the augment and switch groups. The overall incidence proportion of any distressing event was 0.78 [95% confidence interval (CI) 0.72-0.84] in the augment group and 0.80 (95% CI 0.74-0.85) in the switch group. This contrasts unmatched analyses where distressing adverse events were less common in the augment group than the switch group (risk ratio 0.85, 95% CI 0.81-0.90).

Conclusion: After adjusting for selection bias inherent in the STAR*D comparison of augment with switch, clinically meaningful differences in the adverse event profiles between these treatment strategies were not observed.