A Meta-analysis of Inositol for Depression and Anxiety Disorders

Objective: This study is a meta-analysis of inositol as a treatment for depression and anxiety disorders.

Methods: PubMed, Cochrane Library database, and PsycINFO were searched up to 14 August 2013. A systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials (RCTs) were conducted comparing inositol for depressed or anxiety disorder patients.

Results: Seven RCTs in depression (two bipolar depression studies, one bipolar depression and major depressive disorder (MDD) study, two MDD studies, and two premenstrual dysphoric disorder (PMDD) studies) (n = 242) were identified. Four RCTs in anxiety disorders (two obsessive-compulsive disorder studies, one panic disorder study, and one posttraumatic stress disorder study) (n = 70) were also identified. There were no statistically significant effects of inositol on depressive, anxiety, and obsessive-compulsive symptoms and discontinuation (all-cause, side effects, and worsening psychiatric symptoms). However, inositol had marginally more responders in depression than placebo (p = 0.06), and inositol showed a trend towards superior efficacy for depressive symptoms in patients with PMDD (p = 0.07). Inositol marginally caused gastrointestinal upset compared with placebo (p = 0.06).

Conclusions: Our results suggest that inositol may be beneficial for depressed patients, especially those with PMDD. The main limitation of this report is that a small number of studies were included in this meta-analysis.