Methods: Eighty one patients (males and females aged 18-65, with a score ≥20 on the Yale-Brown Obsessive Compulsive Scale, stable selective serotonin reuptake inhibitors or cognitive behavioral therapy for 2 months) will be recruited. Patients will be randomized 2:2:1:1 TMS+DCS, TMS+Placebo, Sham+DCS or Sham+Placebo. Participants who do not have recent bloodwork will have laboratory tests to rule out haematological, hepatic, and renal disease, and participants will be screened for suicidal ideation. The dose of DCS will be 100mg, taken daily for four weeks. Clinical outcomes will be quantified using the Yale-Brown Obsessive Compulsive Scale, a gold standard clinician rated instrument for OCD, as well as measures of depression and anxiety. Participants will complete a short battery of cognitive tests and questionnaires to measure self-reported symptoms of depression, anxiety and quality of life. Fecal samples will be taken at baseline, week 4 and week 8 to characterize any changes in the microbiome. Participants clinical symptoms will be evaluated again one-month after treatment. At this time, all participants who received sham-rTMS will be offered an additional 4 weeks of open label rTMS.
Obsessive Compulsive Disorder (OCD)is a common and debilitating illness. For an unacceptable proportion of patients, depressive symptoms remain impairing despite multiple treatments.~In August 2018, the FDA approved transcranial magnetic stimulation (TMS) for the treatment of OCD based on a large study demonstrating efficacy. Our neurophysiological data and clinical data in depression suggests that we can enhance the effects of TMS by using an adjunctive medication called D-Cyloserine (DCS, 100mg) in conjunction with stimulation. The mechanism by which this is achieved is called synaptic plasticity, or the activity dependent changes that occur with brain stimulation.~Research Question and Objectives: To conduct a randomized sham- and placebo-controlled trial of DCS in adjunct with rTMS in OCD. Participants will be randomized to receive 100mg of DCS or placebo together with TMS.