Does anxiety moderate the efficacy of mirtazapine in patients with treatment resistant depression? A secondary analysis of the mir trial

Rifkin-Zybutz, R.; Macneill, S.; Dickens, C.; Campbell, J.; Chew-Graham, C.; Peters, T.; Wiles, N.; Kessler, D.

Abstract

Introduction:
Mirtazapine has been shown to be effective in treating patients with both depression and anxiety symptoms.1 This has not been examined in primary care.

Objectives:
We examined whether anxiety moderated the effect of mirtazapine compared with placebo in patients with treatment resistant depression (TRD).

Methods:
MIR is a placebo-controlled trial of the addition of mirtazapine to an SSRI/SNRI antidepressant in TRD that did not find a clinically meaningful effect on depressive symptoms over 12 weeks.2 We split participants into three groups by baseline GAD-7 score : severe (GAD-7 >16), moderate (GAD-7 11-15), no/mild (GAD-7 ≤10). We used linear regression and likelihood ratio testing of interaction terms to assess how baseline anxiety altered the response of participants to mirtazapine as measured by endpoint GAD-7 and BDI-II scores.

Results:
Patients with higher anxiety got more anxiolytic benefit from mirtazapine compared to placebo (p = 0.04). Participants with severe anxiety (n=99/420) receiving mirtazapine had larger reductions in GAD-7 score (Mean difference (MD) 2.82, 95% CI 0.69 to 4.95) and larger decreases in BDI-II score (MD 6.36, 95% CI 1.60 to 10.84). Conversely those with no/mild anxiety (n=245/420) had no anxiolytic benefit (MD -0.28, 95% CI -1.60 to 1.05) compared to placebo.

Conclusions:
This extends evidence for mirtazapine’s anxiolytic effectiveness to primary care patients with TRD. These results may inform targeted prescribing based on concurrent anxiety symptoms, although these conclusions are limited by the post-hoc nature of this analysis. References 1. Fawcett J, Barkin RL. J Clin Psychiatry. 1998;59(3):123-7. 2. Kessler DS, et al. BMJ (Online). 2018;363.

Citation

Rifkin-Zybutz, R., Macneill, S., Dickens, C., Campbell, J., Chew-Graham, C., Peters, T., …Kessler, D. (2020, July). Does anxiety moderate the efficacy of mirtazapine in patients with treatment resistant depression? A secondary analysis of the mir trial. Poster presented at 28th European Congress of Psychiatry, Madrid, Spain

• Presentation Conference Type: Poster
• Conference Name: 28th European Congress of Psychiatry
• Conference Location: Madrid, Spain
• Start Date: Jul 4, 2020
• End Date: Jul 7, 2020
• Deposit Date: Jun 22, 2023
• Keywords: Treatment resistance; Mirtazapine; Anxiety
• Publisher URL: https://www.cambridge.org/core/journals/european-psychiatry/article/eposter-viewing/D36C52D45873073B3F9642A91F6EB46C