The Therapeutic Impact of Plant-Based and Nutritional Supplements on Anxiety, Depressive Symptoms and Sleep Quality among Adults and Elderly: A Systematic Review of the Literature.

Following the PRISMA guidelines, 76 studies were included in this review. We used the revised Risk of Bias tool (RoB2) to assess the quality of all included randomized control trials. A qualitative data synthesis was conducted. Overall, we found several valuable insights from the evidence in the literature, including evidence that demonstrates the benefits of probiotics and vitamin B complexes on anxiety symptoms, depressive symptoms, and sleep quality. Implication of Key Findings: This review provides the most updated findings in the literature on the topic, including an abundance of research that was published in the past 5 years. Given the expected rise in negative mental and sleep health outcomes following the pandemic, the supplements and therapeutics identified in this study should be the target of intervention measures to increase their accessibility and affordability and allow them to be incorporated into clinical guidelines of treatment. PROSPERO registration number: CRD42022361130.