Transcranial Magnetic Stimulation (TMS) in Obsessive Compulsive Disorder (OCD): Mechanisms and Biomarkers

This treatment study examines the use of transcranial magnetic stimulation (TMS) in treating people with OCD and investigates what areas of the brain are involved during emotional learning. TMS is a noninvasive method in which a magnetic "coil" is placed near an individual's head and delivers small magnetic pulses into the brain, which produce small electrical currents in the brain, stimulating brain cells that may relieve OCD symptoms. TMS has been FDA approved since 2008 and Health Canada approved since 2002 as a treatment for depression. Our hope is to demonstrate that TMS is a successful treatment option for individuals struggling with OCD symptoms, and to identify the specific areas of the brain that are targeted through TMS. Patients will be randomized (like the flip of a coin) to one of two groups: 6 weeks of daily active TMS, or 6 weeks of daily placebo (sham) TMS sessions. During phase I, participation in this study will last about 8 weeks and patients will be asked to make about 36 visits to our clinics at the MGH main campus and the MGH Charlestown Navy Yard campus. Patients will also participate in MRI scanning sessions and clinical assessments. If patients' symptoms do not improve after phase I, they will be invited to participate in phase II. During phase II, patients receive 30 active TMS sessions over 6 weeks, as well as MRI scans and clinical assessments. Part of the MRI scanning sessions will include participating in a task that uses mild, half-second electric shocks to fingers. The electric current will be generated from a 9V battery (e.g., battery in a smoke alarm), and is much less annoying than a static shock. In order to set the level of the current to be used during the study, we will begin at a level below what patients will be able to feel, and then increase in gradual steps with permission. Patients will be asked to stop the increase at a level of the current that they find highly annoying but not painful. The level of current that patients select during this trial procedure, and no higher level, will be used during the study so that they will not receive any painful electric shocks. The purpose of the electric shock is to create a situation in which emotional learning may occur. Patients will receive no more than ten of these electric shocks. Compensation is provided for clinical assessments and MRI scan sessions.