Assessing the Effectiveness of Repetitive Transcranial Magnetic Stimulation in the Treatment of Obsessive- Compulsive Disorder

Objective. Obsessive-compulsive disorder (OCD) is a frequent and disabling neuropsychiatric disorder with a lifetime prevalence of 3%. About 40% to 60% of patients show no or just partial symptom improvement to treatment with a first-line drug and cognitive behavior therapy. Ten percent of patients remain treatment refractory despite several treatments. For these patients, repetitive Transcranial Magnetic Stimulation (rTMS) has been suggested as a treatment option. Method. We investigated the efficacy of rTMS on the Supplementary Motor Area (SMA) in 16 right handed pharmaco-resistant OCD patients in an outpatient setting. The patients have been diagnosed with OCD by two psychiatrists and referred for rTMS intervention. Patients received 16 sessions of low frequency (0.5 HZ) rTMS on SMA,100% motor threshold, 1200 stimuli/day for 40 minutes every other day. OCD, depression, and anxiety symptoms were measured at baseline, 2, 6, and 12 weeks by Yale-Brown Obsessive Compulsive Scale(Y-BOCS) and Hamilton Depressive and Anxiety rating scales (HAM-D and HAM-A). We assessed the side effects of rTMS by a self-administrative questionnaire. Results. Patients' scores in Y-BOCS, HAM-D, and HAM-A were significantly decreased following rTMS treatment. The baseline and 12 weeks scores of Y-BOCS were 28.94 and 18.31 (P-value < 0.01), HAM-D were 14.69 and 7.94 (P-value <0.01) and HAM-A were 16.38 and 6.94 (P- value < 0.01), respectively. The patients reported no serious side effects of rTMS except two case that reported light headach. Conclusion. This study showed that low-frequency rTMS on SMA improved OCD, anxiety, and depression symptoms after 16 sessions.