Effects of curcumin on depression, anxiety, and stress symptoms in adults: a GRADE-assessed systematic review and dose–response meta-analysis
Abstract
Background Curcumin, a bioactive polyphenol extracted from Curcuma longa, has demonstrated antioxidant, anti-inflammatory, and neuroprotective properties that may benefit mental health. However, evidence from randomized controlled trials (RCTs) remains inconsistent. Objective This systematic review and dose–response meta-analysis aimed to quantitatively assess the effects of curcumin supplementation on depression, anxiety, and stress in adults. Methods Electronic databases including PubMed, Scopus, Web of Science, and Google Scholar were searched up to December 2025 for RCTs. Two reviewers independently conducted study selection, data extraction, and risk-of-bias assessment. Pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Subgroup, meta-regression, sensitivity, dose–response, and time–response analyses were conducted. Moreover, publication bias and certainty of evidence were evaluated. The study protocol was registered in the PROSPERO database (CRD420251208049). Results Twenty-six RCTs encompassing 1,491 participants were included. Curcumin supplementation significantly reduced symptoms of depression (SMD = –1.53; 95% CI: –2.05 to –1.02), anxiety (SMD = –1.67; 95% CI: –2.42 to –0.93), and stress (SMD = –1.71; 95% CI: –3.37 to –0.06) compared with placebo. Dose–response analysis indicated a significant nonlinear association, suggesting that higher curcumin doses (>1.5 g/day) were associated with greater reductions in depressive symptoms. Subgroup analyses showed slightly greater improvements among female participants and those experiencing psychological distress. Conclusions Curcumin supplementation may provide a potential benefit for depression, anxiety, and stress; however, substantial between-study heterogeneity and moderate-to-low certainty of evidence limit confidence in the generalizability of these findings. Further well-designed RCTs are warranted to confirm these findings.