What do systematic reviews say?

Mirtazapine adjunct vs placebo adjunct

It is very uncertain whether mirtazapine adjunct changes mental state: overall mental state ‐ clinically important change* compared with placebo adjunct (very low certainty).

• Mirtazapine adjunct for people with schizophrenia 2018 · Cochrane Headline outcomes only
  RR 0.69 [0.51, 0.92]
  2 studies · 77 participants
  Very low