Clinical Use of Curcumin in Depression: A Meta-Analysis.

INTRODUCTION: There is growing interest in the use of curcumin, a plant polyphenol with potent anti-inflammatory, anti-oxidant, and neuroprotective properties, as a novel antidepressant. Clinical trials have yielded conflicting conclusions pertaining to its effectiveness in depression. A meta-analysis of the topic, which has not been done until now, is therefore necessary to summarize current evidence and generate hypotheses for further research.

METHODS: Using the keywords [curcumin OR diferuloylmethane OR curcuminoid OR turmeric OR Indian saffron] AND [depression OR MDD OR suicide], a preliminary search on the PubMed, Ovid, Clinical Trials Register of the Cochrane Collaboration Depression, Anxiety and Neurosis Group (CCDANTR), and Cochrane Field for Complementary Medicine database yielded 2081 articles published in English between January 1, 1960, and August 1, 2016.

RESULTS: Six clinical trials with a total of 377 patients were reviewed, comparing the use of curcumin to placebo. In patients with depression, the pooled standardized mean difference from baseline Hamilton Rating Scale for Depression scores (pooled standardized mean difference -0.344, 95% confidence interval -0.558 to -0.129; P = .002) support the significant clinical efficacy of curcumin in ameliorating depressive symptoms. Significant anti-anxiety effects were also reported in 3 of the trials. Notably, no adverse events were reported in any of the trials. Most trials had a generally low risk of bias, except for an open trial of curcumin and a single-blinded study.

LIMITATIONS: Because of the small number of studies available, a funnel plot or sensitivity analysis was not possible. Evidence on the long-term efficacy and safety of curcumin is also limited as the duration of all available studies ranged from 4 to 8 weeks.

CONCLUSIONS: Curcumin appears to be safe, well-tolerated, and efficacious among depressed patients. More robust randomized controlled trials with larger sample sizes and follow-up studies carried out over a longer duration should be planned to ascertain its benefits.