Repetitive TMS has been shown to be an effective therapeutic tool for the treatment of several neuropsychiatric disorders including MDD and schizophrenia, but investigations into its utility in OCD are very preliminary. In a study of 12 OCD patients single session stimulation of the right lateral prefrontal cortex (20 Hz, 80% motor threshold, for 20 minutes) resulted in a decrease in compulsive urges for eight hours in contrast to the left prefrontal cortex which was associated with more modest response . Sachdev et al randomly assigned 12 individuals to receive right or left dorsolateral prefrontal stimulation (10 Hz,110% resting motor threshold, 15 minutes 5 sessions/week for 2 weeks). Subjects showed significant improvement at two weeks and 1-month follow-up, regardless of lateralit. A randomized controlled trial comparing right prefrontal stimulation to sham treatment in 18 OCD subjects was negative, however low frequency (1 Hz) stimulation was used in contrast to previous reports (110% motor threshold, 20 minutes 3 times/week for 6 weeks). Most recently a small study of 10 individuals with OCD and/or Tourette's syndrome found benefit with low-frequency stimulation of the supplementary motor area (1 Hz, 100% motor threshold, 20 minutes 5 sessions/week for 2 weeks). Notably subjects were treatment-resistant in both this and the Sachdev study. Thus although this limited literature precludes any definitive conclusions, it suggests that rTMS may be of benefit in refractory OCD.