Many patients view psychotropics with skepticism and fear and view nutritional supplements as more consistent with their values and beliefs. The purpose of this review was to critically evaluate the evidence base for nutritional supplements in the treatment of bipolar depression (BD). A literature search for all randomized, controlled clinical trials using nutritional supplements in the treatment of BD was conducted via PubMed and Ovid MEDLINE computerized database. The studies were organized into essential nutrients/minerals, nonessential nutrients, and combinations of nutritional products. Among essential nutrients/minerals, omega-3-fatty acids (O3FAs) have the strongest evidence of efficacy for bipolar depression, although some studies failed to find positive effects from O3FAs. Weak evidence supports efficacy of vitamin C whereas no data support the usefulness of folic acid and choline. Among nonessential nutrients, cytidine is the least supported treatment. Studies of N-acetylcysteine have not resolved its efficacy in treating acute depressive episodes relative to placebo. However, one study demonstrates its potential to improve depressive symptoms over time and the other, though nonsignificant, suggests it has a prophylactic effect. Studies of inositol have been mostly negative, except for 1 study. Those that were negative were underpowered but demonstrated numerically positive effects for inositol. There is no evidence that citicholine is efficacious for uncomplicated BD depression, though it may have value for comorbid substance abuse among BD patients. Finally, combination O3FA-cytidine lacks evidence of efficacy. The findings of this review do not support the routine use of nutritional supplements in the treatment or prophylaxis of BD depression. Studies with more rigorous designs are required before definitive conclusions can be made. Despite the inadequacy of the existing data, clinicians should remain open to the value of nutritional supplements: after all, lithium is a mineral too.
Keywords: bipolar disorder; clinical trials; depression; pharmacotherapy; treatment.
© 2013 Wiley Periodicals, Inc.