Magnesium and mood disorders: systematic review and meta-analysis

BACKGROUND: Magnesium (Mg(2+)) has received considerable attention with regards to its potential role in the pathophysiology of the mood disorders, but the available evidence seems inconclusive. AIMS: To review and quantitatively summarise the human literature on Mg(2+) intake and Mg(2+) blood levels in the mood disorders and the effects of Mg(2+) supplements on mood. METHOD: Systematic review and meta-analyses. RESULTS: Adherence to a Mg(2+)-rich diet was negatively associated with depression in cross-sectional (odds ratio = 0.66) but not in prospective studies. Mg(2+) levels in bodily fluids were on average higher in patients with a mood disorder (Hedge's g = 0.19), but only in patients treated with antidepressants and/or mood stabilisers. There was no evident association between Mg(2+) levels and symptom severity. Mg(2+) supplementation was associated with a decline in depressive symptoms in uncontrolled (g = −1.60) but not in placebo-controlled trials (g = −0.21). CONCLUSION: Our results provide little evidence for the involvement of Mg(2+) in the mood disorders. DECLARATION OF INTEREST: None.