New research shows that patients with SSRI-resistant depression can benefit from augmentation therapy with the medical food L-methylfolate. The study, published in the American Journal of Psychiatry, demonstrates the safety superior response and tolerability of L-methylfolate, (available by prescription in the U.S. under the brand name Deplin®) in patients with Major Depressive Disorder (MDD). Approximately two thirds of people living with depression will be unsuccessful with their first round of antidepressant monotherapy. Yet, many are unaware that certain metabolic imbalances inhibit adequate response to treatment with traditional serotonin reuptake inhibitors (SSRI's) alone.

"Deplin® can be part of a novel approach to depression therapy that is effective in patients that do not respond to traditional SSRI's, as well as relatively safe and well-tolerated compared to almost all alternative options" said Dr. George Papakostas, lead author of the study. "The efficacy to the molecule has been proven in a randomized controlled trial examining at 15mg daily dose, and we are eager to see how it can benefit certain subsets of the depressive population with SSRI-resistant depression."

"The results of this clinical trial are very encouraging," said Dr. Maurizio Fava, the study's lead investigator. "It will be exciting to see additional research involving L-methylfolate as an adjunct therapy for MDD. If continued to be proven to help patients achieve a superior response in the treatment of depression, this could be a true game-changer in the field."

Two double-blind studies involved 223 patients with SSRI-resistant MDD and found that 15mg per day of adjunctive L-methylfolate can be a useful treatment strategy for SSRI partial and non-responders with MDD, while 7.5mg daily did not appear to be sufficient to treat MDD.

In the first trial, 148 outpatients with SSRI-resistant MDD were enrolled in a 60-day multi-center study divided into two, 30-day periods (phases I and II). Patients were randomized in a 2:3:3 fashion to receive either adjunctive L-methylfolate for 60 days (7.5mg/day, phase I; 15mg/day, phase II), adjunctive placebo for 30 days followed by adjunctive L-methylfolate for 30 days (7.5 mg/day), or adjunctive placebo for 60 days. SSRI doses were kept constant during the double-blind phase of the study. The second trial, which involved a total of 75 patients, was identical in design to the first, except for a target dose of 15mg/day of adjunctive L-methylfolate throughout both phases.

While the first trial showed no difference in outcome between the adjunctive L-methylfolate 7.5mg/day and adjunctive placebo, the results of the second trial indicated significantly greater outcomes with adjunctive L-methylfolate 15mg/day versus adjunctive placebo on both co-primary outcome measures and a number of secondary outcome measures. Twice as many patients taking adjunctive L-methylfolate 15mg/day achieved response in 30 days (response: ≥50% reduction in depressive symptoms) and experienced 84% greater reduction in depressive symptoms compared to patients given adjunctive placebo (p=0.04, p=0.05 respectively). The number needed to treat for response was between 5 and 6 in favor of adjunctive L-methylfolate 15mg/day.

There were no statistically significant differences in discontinuation due to adverse events between L-methylfolate and placebo-treated patients.