Medicinal plants and plant-based traditional medicine: Alternative treatments for depression and their potential mechanisms of action.

Background: Clinical depression is a serious public health issue that affects 4.7 % of the world's population and can lead to suicide tendencies. Although drug medications are available, only 60 % of the depressed patients respond positively to the treatments, while the rest experience side effects that resulted in the discontinuation of their medication. Thus, there is an urgent need for developing a new anti-depressant with a distinct mode of action and manageable side effects. One of the options is using medicinal plants or plant-based traditional medicine as alternative therapies for psychiatric disorders. Objectives: Therefore, the objective of this review was twofold; to identify and critically evaluate anti-depressant properties of medicinal plants or those incorporated in traditional medicine; and to discuss their possible mechanism of action as well as challenges and way forward for this alternative treatment approach. Methods: Relevant research articles were retrieved from various databases, including Scopus, PubMed, and Web of Science, for the period from 2018 to 2020, and the search was updated in September 2024. The inclusion criterion was relevance to antidepressants, while the exclusion criteria included duplicates, lack of full-text availability, and non-English publications. Results: Through an extensive literature review, more than 40 medicinal plant species with antidepressant effects were identified, some of which are part of traditional medicine. The list of the said plant species included Conclusion: This pool of identified plant species is hoped to offer health care professionals the best possible alternatives of anti-depressants from natural phytocompounds that are efficacious, safe and affordable for applications in future clinical settings.