A recent issue of Nutritional Neuroscience featured a review study of possible links between magnesium intake and depression: Magnesium and depression: a systematic review.
The incidence of depression is increasing worldwide. Much is still unknown about the possible role of magnesium in depression prevention and treatment. Magnesium has an effect on biological and transduction pathways implicated in the pathophysiology of depression. The possible role of magnesium in depression prevention and treatment remains unclear….
Magnesium seems to be effective in the treatment of depression but data are scarce and incongruous. Disturbance in magnesium metabolism might be related to depression. Oral magnesium supplementation may prevent depression and might be used as an adjunctive therapy. However, more interventional and prospective studies are needed in order to further evaluate the benefits of magnesium intake and supplementation for depression.
So, there’s at least some evidence for the link between low magnesium and depression, which I discussed at more length in my new book. Also, for a bit more speculative take that’s highly favorable to magnesium treatment of depression, see Magnesium and major depression (pdf).
How might magnesium work in depression? A group of scientists recently discovered that, in mice, low magnesium intake was associated with changes in the levels of four key proteins in the brain.
There is evidence to suggest that low levels of magnesium (Mg) are associated with affective disorders, however, causality and central neurobiological mechanisms of this link are largely unproven. We have recently shown that mice fed a low Mg-containing diet (10% of daily requirement) display enhanced depression-like behavior sensitive to chronic antidepressant treatment. … Collectively, these findings provide first evidence of low magnesium-induced alteration in brain protein levels and biochemical pathways, contributing to central dysregulation in affective disorders.
It’s been estimated that up to 60% of Americans do not get the recommended amount of magnesium in the diet, which could go some way toward explaining rising levels of depression.
I’ve noted before that magnesium citrate is the best absorbed form of magnesium, so if you want to supplement, that form is the one to go with – not the common drugstore form, magnesium oxide, which is barely absorbed at all.