A systematic review of research on the value of pharmaceutical-grade nutritional supplements, or ‘nutraceuticals,’ in depression treatment has found that several do indeed improve depression symptoms.
The 2016 review by Jerome Sarris and colleagues in the American Journal of Psychiatry found that the following nutraceuticals primarily produced positive results compared to placebo: omega-3 fatty acids (primarily EPA or ethyl-EPA); vitamin D; l-methylfolate (a more potent form of folic acid); and S-adenosyl methionine or SAMe, a beneficial compound created from toxic homocysteine with the help of folate.
Editor’s Note: Most of these compounds can also be useful in bipolar depression. Omega-3 fatty acids and vitamin D are helpful to many patients. L-methylfolate is particularly helpful to the 30% of the population with a MTHFR deficiency that interferes with the ability of folate to break down homocysteine. SAMe is an exception—while it is effective in unipolar depression, it may cause switching into mania in patients with bipolar disorder.
The researchers identified a few additional nutraceuticals that each had one study supporting their use—creatine, sometimes used by weightlifters to provide extra energy to muscles; folinic acid, which can protect bone marrow and other cells during chemotherapy; and a combination of amino acids.
Results from studies that compared other compounds to placebo were mixed. Those included studies of zinc, folic acid, vitamin C, and the amino acid tryptophan. A study of inositol, a compound found in plants that is not normally digestible, had nonsignificant results.
No serious side effects were observed in any of the studies of nutraceuticals, though some caused minor digestive disturbances.
Editor’s Note: Another beneficial nutraceutical that did not appear in the review article is N-acetylcysteine. In 6- to 8-week studies, NAC improved depression and anxiety compared to placebo. It also improved bipolar depression and reduced many habits and additions in non-bipolar patients. These include cocaine and gambling addition, alcohol and nicotine use, trichotillomania (compulsive hair-pulling) and obsessive compulsive disorder (OCD).
MTHFR is an enzyme needed for the body to break down vitamin B9, also known as folate or folic acid. It also helps convert the toxic amino acid homocysteine into the antidepressant amino acid s-adenysl-methionine. However, a significant segment of the population (some estimate 40%) have a genetic mutation in the MTHFR gene that interferes with the body’s ability to break down B vitamins and is linked to higher levels of homocysteine. MTHFR mutations are also linked to depression.
A 2016 study by Arnold W. Mech and Andrew Farah in the Journal of Clinical Psychiatry found that treating people with major depression and a MTHFR deficiency using a combination of micronutrients and already-broken-down B vitamins improved their depression and reduced their homocysteine levels compared to placebo.
The study included 330 adult patients with major depression and one of two genetic variants in the MTHFR gene—C677T or A1298C. Of those who received the metabolized vitamins, 82.4% showed reduced homocysteine levels. Those who received placebo showed a small average increase in homocysteine. The vitamin group also saw a large drop in depression symptoms on average after 8 weeks, with 42% achieving full remission. There were no side effects.
These findings suggest that homocysteine levels play a role in depression and that metabolized B vitamins can be an effective treatment for depression, particularly in those with a MTHFR deficiency. A metabolized form of folate that is commercially available is called L-methylfolate.
A 2012 study by Geoge I. Papkostas and colleagues found that 15mg/day of the nutritional supplement l-methylfolate calcium (a form of the B vitamin folate that the body can more readily use) improved depression in people who had not responded adequately to treatment with a selective serotonin reuptake inhibitor (SSRI) antidepressant. In a follow-up study by Richard C. Shelton and colleagues published in the Journal of Clinical Psychiatry in 2015, the same researchers further analyzed these data and found that l-methylfolate worked better in patients who were overweight (with body mass indexes (BMIs) of 30 or above) and those who had higher than average levels of inflammation at the beginning of the study. Inflammatory markers linked to greater improvement with l-methylfolate included TNF-alpha, IL-8, high sensitivity CRP, and leptin. In overweight participants, higher than average levels of IL-6 were also linked to more improvement on l-methylfolate.
While the nutritional supplement folate (also known as folic acid or vitamin B9) can be useful for depression, there appears to be one instance when augmentation with regular folate could be counterproductive. In those with a transport defect associated with a MTHR (methyl tetrahydrofolate reductase) deficiency, folate can compete with l-methylfolate for uptake into the brain. Folate would thus limit the beneficial effects of l-methylfolate supplementation, which is required for this 15% of the population.
The B vitamin folate has been shown to be a useful augmentation treatment for patients who are nonresponsive or only partially responsive to selective serotonin reuptake inhibitor (SSRI) antidepressants. Treatment with folate works even in those who are not folate-deficient at baseline.
When folate is broken down in the body by reductase enzymes, it turns into the active form L-methylfolate, and crosses the blood-brain barrier. Maurizio Fava and colleagues at Massachusetts General Hospital (MGH) performed two placebo-controlled, randomized studies of L-methylfolate for depression. There was significantly greater improvement when SSRIs were augmented with L-methylfolate than when they were augmented with placebo. The results were significant with the use of 15mg of L-methylfolate, but not with 7.5mg, suggesting dose-related effects. Read more