Depression presents an enormous disease burden, with a reported 350 million people worldwide suffering from the disease, but traditional SSRI treatments carry a burden of their own -- in dollars and side effects. New clinical research published in PLoS One shows that over-the-counter magnesium appears safe and effective to treat mild to moderate depression.

Critical to such body functions as heart rhythm, blood pressure and bone strength, the mineral magnesium plays a role in combating inflammation in the body and has been proven to have an association with depression. However, few clinical trials have studied the supplement's effects.

Emily Tarleton, MS, RD, CD, a graduate student in Clinical and Translational Science and the bionutrition research manager in the University of Vermont's Clinical Research Center, and colleagues conducted a clinical trial of over-the-counter oral magnesium tablets for mild-to-moderate depression. Their results showed that magnesium is safe and effective and comparable to prescription SSRI treatments in effectiveness.

The researchers at the University of Vermont's Larner College of Medicine conducted an open-label, blocked, randomized cross-over trial involving 126 adults in outpatient primary care clinics. The study participants, who were currently experiencing mild-to-moderate depression, had a mean age of 52, with 38 percent of them male. Participants in the active arm of the study received 248 milligrams of elemental magnesium per day over six weeks, while those in the control arm received no treatment. Depression symptom assessments were conducted on all participants on a bi-weekly basis.

The study team found that in 112 participants with analyzable data, consumption of magnesium chloride for six weeks resulted in a clinically significant improvement in measures of depression and anxiety symptoms. In addition, these positive effects were shown quickly, at two weeks, and the supplements were well tolerated and similarly effective regardless of age, sex, or use of antidepressants, among other factors.

"This is the first randomized clinical trial looking at the effect of magnesium supplementation on symptoms of depression in U.S. adults," says Tarleton. "The results are very encouraging, given the great need for additional treatment options for depression, and our finding that magnesium supplementation provides a safe, fast and inexpensive approach to controlling depressive symptoms."

Tarleton and colleagues say the next step is to see if their promising results can be replicated in a larger, more diverse population.