Study of Magnetic Brain Stimulation in Treatment of Obsessive Compulsive Disorder (rTMS)

The Efficacy of Deep Repetitive Transcranial Magnetic Stimulation in Treatment of Obsessive Compulsive Disorder, a Double Blind Randomized Clinical Trial

In a preliminary pilot study, the investigators tested the efficacy of rTMS over the medial prefrontal cortex in symptom profiles of obsessive compulsive disorder (OCD) patients. This study revealed considerable benefit in using rTMS for the treatment of OCD. In the current proposal, in a randomized clinical trial, the investigators aim to further evaluate the efficacy of rTMS in OCD in a larger sample size and for a longer period. Studies into the efficacy of rTMS in other psychiatric disorders such as depression have consistently shown that extension of the treatment to four weeks significantly increased the effect size. In the pilot study, the investigators applied rTMS for only two weeks. Although all patients consistently showed improvement in their symptoms, none of them showed complete remission of their OCD. Here, the investigators hypothesize that longer duration of rTMS treatment will have greater benefit in OCD symptom reduction.

The purpose of study is to examine the efficacy of rTMS over the medial prefrontal cortex in the treatment of OCD. rTMS will be provided to OCD patients in a randomized double blind controlled setting, and the investigators hypothesize that in this setting the treatment group would still show significant improvement in OCD symptoms as compared to the sham group. rTMS will be applied for four weeks on OCD patients and the investigators will assess improvement after four weeks of rTMS. The investigators hypothesize that patients will show significantly greater improvement after four weeks of rTMS vs. two weeks of rTMS.

Recordings: baseline; after two weeks of rTMS; after four weeks of rTMS; monthly for three months following the last session of rTMS

Inclusion Criteria: Diagnosed obsessive compulsive disorder Not currently receiving cognitive behavioural therapy Not currently on any medication or only taking one selective serotonin reuptake inhibitor (SSRI) Exclusion Criteria: History of psychotic episodes History of neurological illness Previous head injury Active alcohol or substance abuse History of seizure disorders Currently pregnant