Acute exacerbation of major depressive disorder following valbenazine treatment for tardive dyskinesia: A case report.

Background: Tardive dyskinesia (TD) is a movement disorder associated with long-term use of dopamine receptor-blocking agents. Valbenazine, a selective vesicular monoamine transporter 2 (VMAT2) inhibitor, effectively reduces TD symptoms, but it may also trigger or worsen depressive symptoms by reducing central dopamine and serotonin availability.

Case presentation: We report the case of a 52-year-old woman with major depressive disorder (MDD) and oral dyskinesia who experienced an acute mood deterioration after she began taking valbenazine 40 mg/day. She developed TD while receiving antipsychotic treatment for depression. After she achieved partial psychiatric improvement on lurasidone, we started valbenazine to address her dyskinesia. Within hours of the first dose, she reported markedly worse depressive symptoms, heightened anxiety, and significant functional decline, even though her dyskinesia improved. Her Hamilton Depression Rating Scale score increased from 30 before valbenazine to 40 the next day. We stopped valbenazine, and over the following month, she gradually regained mood stability.

Conclusion: This case shows that valbenazine can acutely worsen preexisting depression. Clinicians should actively evaluate psychiatric history, assess current mood stability before prescribing, and monitor patients closely to identify and address mood changes promptly.