Lopresti AL, Maes M, Maker GL, Hood SD, Drummond PD. Curcumin for the treatment of major depression: A randomised, double-blind, placebo controlled study. J Affect Disord. October 2014;167:368-375.

Curcumin is one of the major bioactive components in the spice turmeric (Curcuma longa, Zingiberaceae), usually comprising 2-8% of most turmeric preparations. Curcumin is part of a group of strong antioxidant compounds which can influence a large array of pathways related to depression. Several in vivo studies have demonstrated curcumin's antidepressant activity via serotonergic, dopaminergic, neuroprotective, and hypothalamic-pituitary-adrenal (HPA)-modulating effects. Previous human studies on curcumin's efficacy in treating depression have produced inconsistent results.^1,2 Hence, the purpose of this randomized, double-blind, placebo-controlled study was to improve evaluation into the antidepressant effects of curcumin as a treatment for major depressive disorder.

Patients (n = 56, aged 18-65 years) were selected based on an Inventory of Depressive Symptomatology self-rated version (IDS-SR₃₀) score of ≥14, and diagnosed with major depression by the first author of the study. Pharmaceutical antidepressant therapy or psychological therapy were permitted if treatment was stable throughout the study and commenced at least 8 weeks prior to the study. Exclusion criteria included smoking and major health or mental disorders.

Patients received either placebo or a 500-mg capsule twice daily for 8 weeks of curcumin (BCM-95^®; Biocurcumax^TM; Arjuna Natural Extracts Ltd; Kochi, India; imported and sold in the United States as CuraMed^® by EuroPharma; Green Bay, Wisconsin), containing 440 mg of curcuminoids (347 mg curcumin, 84 mg desmethoxycurcumin, and 9 mg bisdemethoxycurcumin) and 38 mg of turmeric essential oil. The primary outcome measure was IDS-SR₃₀, indicating severity and frequency of depressive symptoms; secondary outcomes included measuring levels of anxiety (state and trait) by the Spielberger State-Trait Anxiety Inventory (STAI). Eighteen patients were diagnosed with atypical depression, and an exploratory analysis was conducted on these patients. Compliance and efficacy was evaluated at weeks 4 and 8.

The results showed the placebo and curcumin treatment groups both had improved outcomes in IDS-SR₃₀ from baseline to week 4. However, from week 4 to week 8, the curcumin group had significantly improved outcomes on the IDS-SR₃₀ total score (P = 0.045), IDS-SR₃₀ mood (P = 0.014), and an improved, but non-significant, trend on the STAI trait score. In the patients with atypical depression, on the STAI trait, the curcumin group significantly improved from baseline to week 4 (P = 0.008) and from week 4 to week 8 (P = 0.025); whereas, the placebo group did not improve. On all measures, there were no significant differences between placebo and curcumin from baseline to 8 weeks. All adverse events (AEs) were of minor severity, and the frequency did not significantly differ between groups.

The authors conclude that the data provide "partial support for the antidepressant and anxiolytic effects of curcumin" in patients with major depressive disorder and atypical depression. This conclusion is based on the continued improvement from week 4 to week 8 in the curcumin group but with the lack of a significant improvement compared with placebo at 8 weeks. The authors hypothesize that the overall non-significant effect between groups at 8 weeks may be attributed to (1) a strong placebo response, (2) the dose of curcumin, (3) that curcumin may be slow-acting and a longer treatment time may be needed to see the full benefits, and (4) approximately 70% of the patients had recurrent depression and may be resistant to treatment. The authors claim that this study has the longest duration of treatment in patients with major depressive disorder of all published studies. Nonetheless, longer studies are needed that have a larger population and evaluate variable doses. Overall, this study demonstrated improved design by utilizing a double-blind placebo control and provides excellent data for where to go next in the evaluation of curcumin for patients with depression.

—Heather S. Oliff, PhD

References

¹Bergman J, Miodownik C, Bersudsky Y, et al. Curcumin as an add-on to antidepressive treatment: a randomized, double-blind, placebo-controlled, pilot clinical study. Clin Neuropharmacol. May-June 2013;36(3):73-77.