The efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms: A systematic review and meta-analysis

Introduction: Curcumin, a potential natural substance is a promising complementary and alternative therapeutic intervention for depression or depressive symptoms. We undertook a systematic review and meta-analysis to evaluate the efficacy and acceptability. Methods: PubMed, EMBASE, PsycInfo, Web of Science, Cochrane Library and ClinicalTrials.gov were searched from the inception up until March 4, 2020. The Outcomes were depressive symptoms, response rates, drop-out rates, and adverse effects. Results: A total of 594 patients from ten trials were subjected to meta-analysis. Three trials were judged to be at high risk of bias, four at unclear risk of bias and three at low risk of bias. Most of the domains for risk of bias were at low risk or unclear risks and three domains at high risks. The pooling results suggested a significant difference in depression or depressive symptoms(SMD= -0.32, 95% CI: -0.50 to -0.13, I-2 = 15%, n=594) and response rates (OR=3.20, 95% CI: 1.28-7.99, I-2 =35%, n=271). However, there was no difference between drop-out rates (OR=1.06, 95% CI: 0.58-1.93, I-2 =0%, n=594), digestive symptoms (OR=1.27, 95% CI: 0.69-2.32, I-2 =0%, n=284) and neurological symptoms (OR=1.08, 95% CI: 0.49-2.36, I-2 =0%, n=284). Subgroup analysis showed depression was associated with a reduction(SMD= -0.35, 95% CI: -0.56 to -0.15, I-2 =7%, n=432) but depressive symptoms were not (SMD= -0.17, 95% CI: -0.61 to 0.26, I-2 =40%, n=162). Conclusions: The evidence quality is low, indicating that there is great uncertainty about the efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms.