Current Umbrella Evidence on Nutraceuticals and Herbal Medicine for Depression in Adults: A Scoping Review

Background: Depression remains a major global health burden, and conventional antidepressants, although effective, are limited by side effects and withdrawal symptoms. Aim: To map umbrella-level evidence on single-agent nutraceutical and herbal interventions for clinically diagnosed depression in adults. Methods: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews and Joanna Briggs Institute guidance. PubMed, PsycINFO, Scopus, and Cochrane Library were searched (2015–2025) for umbrella reviews assessing oral nutraceuticals or herbal medicines for depression. Results: Nine umbrella reviews met inclusion criteria, covering omega-3 fatty acids, vitamin D, probiotics, saffron, St John’s wort, zinc, and folate. Umbrella reviews generally reported potential antidepressant benefits and acceptable safety profiles for several interventions, although trial overlap and heterogeneity limited certainty. Conclusions: Evidence indicates promising but inconsistent efficacy across several nutraceutical and herbal agents. Standardized reporting, consideration of baseline nutrient status, and economic evaluation are needed to clarify their role in depression care.