Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psy-chiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mecha-nisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well con-ducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Automated summary

Polyphenols have potential beneficial mechanisms of action for mental and brain health, involving gut microbiome and gene expression, but individual differences and the potentially pro-oxidant effects of some polyphenols may contribute to mixed clinical results. Further clarification through larger randomized controlled trials incorporating precision medicine methods is needed to determine clinical efficacy and optimal dosing regimens.