This has been an effective and well-tolerated treatment strategy for patients with major depressive disorder who are partial or non-responders to antidepressant therapy?
L-methylfolate 15 mg/day added to SSRIs or as monotherapy can be an effective and well tolerated treatment strategy. It is particularly effective in patients with a genetic polymorphism of the enzyme methylenetetrahydrofolate reductase (MTHFR) which translates into lower serum levels of L-methylfolate.
Kose S et al. L-methylfolate in patients with treatment resistant depression: fulfilling the goals of personalized psychopharmacological therapy. Psych and Clinical Psychopharmacology 2018; 28(4): 359-362. https://doi.org/10.1080/24750573.2018.1552401