B vitamins as adjunct therapies for depressive disorder

The rising prevalence of depressive disorder worldwide requires better interventional avenues. B vitamins are gaining increasing interest as potential therapeutic approaches in this context given current evidence for a bidirectional association between B vitamin deficiency and depressive disorder. We discuss how B vitamins and B vitamin-associated probiotic supplementation may represent an effective adjunctive treatment for depression, and highlight the key metabolic mechanisms involved. We also provide a perspective on the future of this field and advocate for further high-quality clinical trials to assess the benefits of B vitamins in this context and optimize their clinical implementation.