Folinic acid (Leucovorin) as an adjunctive treatment for SSRI-refractory depression.

Low folate is associated with poorer response to selective serotonin reuptake inhibitors (SSRIs) in major depressive disorder (MDD). Folate supplementation in MDD has been studied in other settings with promising results. The objective of this study was to assess the efficacy of methylfolate as an adjunctive treatment among adults with MDD and inadequate response to an SSRI.