Curcumin as a putative antidepressant

Abstract

Due to inadequate efficacy of antidepressants, various new chemical entities and agents of natural origin have been tested for therapeutic efficacy both alone and to augment existing antidepressants, producing varied clinical results. This article summarizes the basic properties of curcumin and its mechanisms of action, with specific emphasis on the etiopathogenesis of depression, preclinical and current clinical evidence, and future research directions, to better understand the possible role of curcumin in treating depression. Curcumin may have antidepressant activities with diverse mechanisms of action involving primarily neurotransmitters, transcription pathways, neurogenesis, the hypothalamic–pituitary–adrenal axis and inflammatory and immune pathways, as demonstrated in various animal and human studies. Current published randomized clinical trials suggest a small, non-significant benefit of curcumin for major depression. More adequately-powered and methodologically improved studies are mandatory.

Keywords:

• antidepressant
• curcumin
• depression
• mechanism of action

Acknowledgements

This work was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI12C0003).

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Although numerous antidepressants are now available, many patients with depression do not achieve adequate responses and remission which are ultimate treatment goal for depression, so there is a continuing need for novel treatment agents for treating patients with depression.

• Curcumin is a natural substance derived from the spice turmeric and it has been proposed to have therapeutic potential in numerous human diseases such as wound healing and dyspepsia.

• Recently, a growing body of evidence from preclinical studies indicates that curcumin is effective as antidepressant through diverse action mechanisms such as antioxidant effect, anti-inflammatory effects, immune regulation, modulation of neurotransmitters and neurogenesis.

• Currently available clinical trial data also indicate putative efficacy of curcumin in the treatment of depression, however, methodological improvement should be mandatory in next adequately powered and well-controlled clinical trials.

• Relatively low bioavailability of curcumin should be substantially improved by advancement of its delivery systems and the development of a better curcumin formulation that maintains its clinical effects is vital for its wide use in clinical practice.