Treatment-resistant depression: does anxiety moderate the efficacy of mirtazapine?

  • Rifkin-Zybutz R & al.
  • J Psychopharmacol
  • 4 Nov 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • The addition of mirtazapine to a selective serotonin reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor was more effective in treating generalised anxiety in patients with treatment-resistant depression (TRD) and severe anxiety symptoms.
  • Mirtazapine may also be more effective in treating depressive symptoms and improving social functioning in those with higher levels of anxiety.
  • Conversely, there appears to be little clinical utility in adding mirtazapine in patients with TRD and without any concurrent anxiety.

Why this matters

  • Findings warrant further research to assess the benefits of mirtazapine in treating TRD with severe symptoms of generalised anxiety.

Study design

  • A secondary analysis of MIR trial including 480 patients with TRD.
  • All patients were stratified into 3 groups based on generalized anxiety disorder score (GAD-7): mild (GAD-7, ≤10), moderate (GAD-7, 11-15) and severe (GAD-7, ≥16).
  • The effect of baseline anxiety on the response of patients to mirtazapine was measured using 12-week GAD-7 and Beck Depression Inventory II (BDI-II) scores.
  • Funding: None disclosed.

Key results

  • At 12 weeks, baseline generalised anxiety moderated the efficacy of mirtazapine as measured by GAD-7 (P=.041) and BDI-II (P=.088).
  • Patients with severe generalised anxiety receiving mirtazapine vs placebo had:
    • lower GAD-7 score (adjusted difference between means [ADM], 2.82, 95% CI, −0.69 to −4.95); and
    • larger reductions in BDI-II score (ADM, −6.36; 95% CI, −1.60 to −10.84).
  • In patients with no/mild generalised anxiety, no anxiolytic (ADM, 0.28; 95% CI, −1.05 to 1.60) or antidepressant benefit (ADM, −0.17; 95% CI, −3.02 to 2.68) was seen with mirtazapine vs placebo.

Limitations

  • Post hoc analysis.