Evaluating the Role of OnabotulinumtoxinA in the Treatment of Major Depressive Disorder

Authors

• Tochukwu Okemezie, University of LynchburgFollow

Specialty

Psychiatry

Abstract

OnabotulinumtoxinA has been investigated as a potential adjunctive treatment for major depressive disorder (MDD). Emerging clinical research suggests that targeted injections into the glabellar region may reduce depressive symptom severity through modulation of facial musculature involved in negative emotional expression. This narrative clinical review synthesizes findings from randomized, double-blind, placebo-controlled trials evaluating onabotulinumtoxinA in adults with MDD. Across studies, depressive symptoms were measured using validated instruments including the Beck Depression Inventory (BDI) and the Montgomery–Åsberg Depression Rating Scale (MADRS). Trials consistently demonstrated greater reductions in depressive symptom scores among participants receiving onabotulinumtoxinA compared with placebo at approximately six weeks following treatment. Mean reductions ranged from approximately 10.7 to 14.7 points on standardized rating scales, with higher response rates observed in treatment groups. Reported adverse events were mild and typically limited to transient headache or injection-site discomfort. The proposed antidepressant mechanism is based on the facial feedback hypothesis, which suggests that inhibition of corrugator and glabellar muscle activity may influence affective processing. Although early findings are promising, the available evidence is derived from relatively small clinical trials with limited follow-up duration. Larger multicenter studies are needed to determine long-term efficacy, safety, and the potential role of onabotulinumtoxinA within existing treatment algorithms for MDD.

Recommended Citation

Okemezie T. Evaluating the Role of OnabotulinumtoxinA in the Treatment of Major Depressive Disorder. University of Lynchburg DMSc Doctoral Project Assignment Repository. 2026; 8(1).