A recently published clinical trial suggests that lurasidone, which is an atypical antipsychotic with strong evidence for efficacy in treating bipolar depression, may be associated with response in patients who, according to DSM5, do not meet criteria for bipolar disorder, but do have evidence of mixed features.
The study points to the importance of industry funded studies in helping to advance the state of knowledge in the field of psychiatry, since it suggests that the “spectrum” view that unipolar depression and bipolar depression exist on a continuum from pure unipolar depression (no mixed features, no cycling) to pure bipolar disorder (rapid cycling bipolar 1).
Trish Suppes and colleagues studied 209 patients with major depression and mixed features (2–3 manic features but not meeting DSM5 criteria for hypomania). This was a six week trial that compared treatment with either lurasidone (20–60 mg/day, flexibly dosed; mean, 36 mg/day) or placebo.
Most of the patients in the study were women (70%; average age 45) and they had a high lifetime history of depressive episodes (4.4).
Like other atypicals, lurasidone antagonizes D2/D3 and 5-HT2 receptors but also shows high affinity for 5-HT7 receptors, implicated in antidepressant efficacy.
Baseline manic symptoms included flight of ideas/racing thoughts (67%) and pressured speech (61%).
Week-6 rates of change on MADRS strongly favored lurasidone, with a large effect size (response, 65% vs. 30% with placebo; NNT, 3; remission, 49% vs 23%; NNT, 4).
Nausea and somnolence occurred in >5% of lurasidone-treated patients; weight increased ≥7% in 1.9%.