Study of 6(S)-5-MTHF Among Selective Serotonin Reuptake Inhibitor-Resistant Outpatients With Major Depressive Disorder

TRD - 2: A Double-Blind, Placebo Controlled Study of 6(S)-5-MTHF Among SSRI-Resistant Outpatients With Major Depressive Disorder (MDD)

The purpose of the study is to test whether oral 6(S)-5-MTHF (Deplin) is safe and effective in relieving depression when it is added to standard kinds of antidepressants called serotonin reuptake inhibitors (SSRIs).

The study consists of two phases, each lasting a total of four weeks (8 weeks total), with visits at the DCRP every 10 days. If the subject is eligible, they will be asked to return two weeks later for a baseline visit, when they will be randomly assigned, like a flip of a coin, to one of three treatment groups: a) drug/drug, b) placebo/drug, c) placebo/placebo (a placebo is a pill that looks like a study drug but contains no active medication). They will have a greater than 50% chance of receiving active medication (Deplin) at some point in the 8 week study.

Neither the subject nor the research staff will know which group the subject is in.

All subjects will be asked to take the study medication in the morning, in addition to their ongoing SSRI treatment.

Inclusion Criteria:

• 18-65 years old
• Meet criteria for current Major Depressive Disorder
• Currently taking an SSRI

Exclusion Criteria:

• Pregnant women
• Unstable medical illness including cardiovascular, hepatic, renal, respiratory, endocrine, neurological, or hematological disease
• Prior course of MTHF augmentation, or intolerance to MTHF at any dose
• Substance use disorders active within the last six months, any bipolar disorder (current or past), any psychotic disorder (current or past)
• Have failed more than 2 adequate antidepressant trials during the current Major Depressive Episode