Folate deficiency has been associated with a higher risk of depressive symptoms, irritability, and other mood disturbances, likely through its role in one‑carbon metabolism, monoamine neurotransmitter synthesis, and methylation processes in the brain. Clinical and epidemiologic studies have found that people with low folate or elevated homocysteine are more likely to experience major depression, and lower folate status has been linked to poorer response to certain antidepressant medications. The encouraging clinical point is that, in folate‑deficient individuals, correcting folate status (often with folic acid or methylfolate, and alongside vitamin B12 when indicated) may improve mood symptoms and, in some cases, enhance antidepressant treatment response, especially when combined with comprehensive psychiatric and lifestyle interventions. This medication is commonly used for Depression.
David Mischoulon, Maurizio Fava. Folate in Depression: Efficacy, Safety, Differences in Formulations, and Clinical Issues. The Journal of Clinical Psychiatry. 2009. Gao S, Khalid A, Amini-Salehi E, Radkhah N, Jamilian P, Badpeyma M, Zarezadeh M. Folate supplementation as a beneficial add-on treatment in relieving depressive symptoms: A meta-analysis of meta-analyses. Food Sci Nutr. 2024 Mar 8;12(6):3806-3818. Reynolds EH, Crellin R, Bottiglieri T, Laundy M, Toone BK, et al. Methylfolate as Monotherapy in Depression. A Pilot Randomised Controlled Trial. J Neurol Psychol. 2015;3(1): 5. Reynolds EH. Folic acid, ageing, depression, and dementia. BMJ. 2002 Jun 22;324(7352):1512-5. Gilbody S, Lightfoot T, Sheldon T. Is low folate a risk factor for depression? A meta-analysis and exploration of heterogeneity. J Epidemiol Community Health. 2007 Jul;61(7):631-7.
Some side effects may be linked to nutrient depletion caused by this medication.
Research suggests that folic acid supplementation can significantly improve the effectiveness of SSRI medications such as fluoxetine (commonly known as Prozac). This benefit seems to be linked to lowering blood levels of homocysteine, an amino acid. Elevated homocysteine levels have been associated with depression. Supplementing with sufficient folic acid may help the body regulate homocysteine levels, potentially creating a more favorable environment for antidepressants to work effectively.
Research suggests the trace mineral chromium may offer some benefits for people experiencing depression, particularly those with atypical depression. Atypical depression is characterized by symptoms like increased appetite, carbohydrate cravings, and weight gain, alongside feelings of sadness and low mood. Studies show chromium supplementation might improve these specific symptoms in people with atypical depression who also have strong carbohydrate cravings. The potential explanation lies in chromium's possible effects on insulin utilization and brain chemicals like serotonin and norepinephrine, both of which are involved in mood regulation. Supplementation with chromium is suggested to support mood and help protect against depression.