The author comments on the article by Andrew Farah on the evidence about the possible efficacy of L-methylfolate as an alternative option to attain remission in people with depression. He explains the implication of a deficiency in the synthesis of serotonin for a patient. He argues that the findings of clinical trials on the efficacy of such drug are limited. He stresses the need for larger scale controlled clinical trials before the drug can be suggested as a first-line treatment.