Adjunctive Treatment With L-methylfolate for Treatment-Resistant Generalized Anxiety Disorder: a Pilot Study

Background: Up to 33.7% of the population are affected by an anxiety disorder during their lifetime according to large populationbased surveys. Generalized anxiety disorder (GAD) has a lifetime prevalence of 2.8% to 6.2% in these studies. GAD is associated with functional, occupational, and quality of life impairments. Certain types of medications and psychotherapies are established treatments for GAD, but only 50% of the patients respond to the first treatment trial. Deficiency of folates and neuroinflammation are two hypothesis that could explain why some patients with anxiety disorders do not respond to the usual treatments. Supplementation with folates could correct these deficiencies and reduce inflammation, thus increasing the success rates for treatments. In studies with major depressive disorder, adjunctive folates were associated to higher remission rates. Other studies indicate that folate supplementation lowers homocysteine levels and inflammation. Objectives: Ascertain if adjunctive treatment with Lmethylfolate can produce improvement in treatment-resistant GAD subjects. Methods: This is a proof-of-concept pilot study, an open-label trial of adjunctive treatment with L-methylfolate in patients with treatment-resistant GAD. Ten adult patients with treatment-resistant GAD who have been on a stable dose of an SSRI or SNRI for at least 12 weeks will receive 15 mg doses of L-methylfolate daily for 8 weeks. Patients with moderate to severe major depressive disorder or suicide risk will not be included. Serum levels of folate, vitamin B12, C-reactive protein, homocysteine, tumor necrosis factor alpha and interleukin 6will be measured before and after the trial.