Prof. Dr. Kemal Arıkan
Psikiyatrist

Obsessive Compulsive Disorder (OCD) and TMS

Obsessive Compulsive Disorder (OCD) is a neuropsychiatric disorder having a prevalence of 2% in America.

Obsessive Compulsive Disorder (OCD)

The symptoms of OCD generally start in the childhood and then turn into a chronic problem that affect the daily life and relationships. Obsessions define the obsessive thoughts that are also named apprehensiveness, while compulsions stand for repetitive behaviors that are described as ritual behaviors. Behaviors like washing hands time after time or checking whether the oven is turned off countless times every night can be given as the examples of “obsessive” behaviors. Though these behaviors differ, affecting the daily lives of the people is the common trait they have.

Pharmacotherapy is useful in the patients at the rate of 40-60%. Furthermore, cognitive behavioral therapy can also be effective for OCD patients. Nevertheless, in the case that pharmacotherapy or psychotherapy is not adequate, new and alternative methods are needed.

Upon the comprehension of the neural circuits present in the pathophysiology of OCD, various non-pharmacological approaches have been developed in the past 10 years to treat OCD. The ever-increasing evidences indicate the dysfunction of three significant areas in the emergence of OCD. These areas are dorsolateral prefrontal cortex, orbitofrontal cortex and supplementary motor area.

Repetitive TMS (rTMS)

Thanks to the magnetic field it creates, Repetitive TMS (rTMS) is capable of changing the activity of the cortex and sub-cortex structures by causing electric currents. It is thought that the rTMS implemented at a low frequency suppresses the OCD symptoms caused by the hypermetabolic activity in the medial prefrontal brain area. The findings obtained as a result of the meta-analysis study carried out showed that an active rTMS significantly decreased the OCD symptoms along with anxiety and depression associated with OCD. It was shown that this activity is mostly present in the orbitofrontal cortex and supplementary motor areas. Moreover, the high activity of the sub-cortex structure named “striatum” is considered to be causing repetitive behaviors.

In a study carried out on experimental animals, the increased activity of the lateral orbitofrontal cortex suppresses striatum. Thus, the occurrence of excessively repetitive behaviors decreases, in other words, compulsive behaviors are treated.

In other study, it was shown that the inhibitor stimulation made on the supplementary motor area via rTMS provided a meaningful development in the symptoms observed in OCD and Tourette’s syndrome, and that this effect lasted for 3 months.

Despite the fact that the studies show that rTMS is effective on the OCD symptoms, the protocols implemented in the studies are becoming different. The studies are required to be carried out on groups of a larger scale in order to standardize the protocol to be implemented at clinics and to support the effectiveness of rTMS on the OCB symptoms with more robust evidences.

The new studies to be conducted with the collaboration between psychiatry and technology are expected to make a contribution to the clinics of the psychiatric disorder in the future.