Vortioxetine for depression in adults: A systematic review and dose-response meta-analysis of randomized controlled trials.

Aim: Major depressive disorder (MDD) is a prevalent psychiatric condition and vortioxetine offers promising antidepressant effects due to its unique pharmacological profile. However, the dose-response relationships of vortioxetine for MDD is not well established. We aimed to conduct dose-response meta-analyses to fill this gap.

Methods: We systematically searched multiple electronic databases for randomized controlled trials of vortioxetine for MDD, with the last search conducted on 08 February, 2024. The dose-response relationship was evaluated using a one-stage random-effects dose-response meta-analysis with restricted cubic spline model. The primary outcome was efficacy (mean change in depression scale score), with secondary outcomes including response, dropout for any reasons (acceptability), dropout for adverse events (tolerability), and any adverse events (safety).

Results: The dose-response meta-analysis comprised 16 studies, with 4,294 participants allocated to the vortioxetine group and 2,299 participants allocated to the placebo group. The estimated 50% effective dose was 4.37 mg/day, and the near-maximal effective dose (95% effective dose) was 17.93 mg/day. Visual inspection of the dose-efficacy curve suggests that a plateau possibly had not been reached yet at 20 mg/day. Acceptability, tolerability and safety decreased as the dose increased. Subgroup analysis indicated that no significant differences were observed in acceptability, tolerability and safety among the dosage groups.

Conclusions: Vortioxetine may potentially provide additional therapeutic benefits when exceeding the current licensed dosage without significantly impacting safety. Conducting clinical trials exceeding the current approved dosage appears necessary to fully comprehend its efficacy and risk.