rTMS investigation of resistant Obsessive-Compulsive Related Disorders: Efficacy of targeting the reward system.

Introduction: Repetitive Transcranial Magnetic Stimulation (rTMS) is not only a therapeutic option but also an investigational tool to explore circuits and subjective dimensions in pathological conditions. Obsessive-Compulsive Related Disorders (OCRDs) shared similarities with Substance Use Disorder (SUD), suggesting the involvement of the reward system. This study aimed to verify the efficacy of targeting the reward system with rTMS in OCRDs. Methods: Patients with trichotillomania, hoarding disorder and skin picking disorder were treated with rTMS over the left DorsoLateral PreFrontal Cortex (DLPFC) at 15 Hz, targeting the reward system via the connection with the nucleus accumbens and the ventral tegmental area. All patients were administered with psychometric scales assessing depression symptoms and severity of OCRDs symptoms at the baseline, at the end of the treatment and a 1-month follow-up. Results: Analysis of the results showed a reduction in symptom severity at the end of the treatment in all three groups ( Discussion: This study adopted with promising results a protocol (15 Hz over the left DLPFC) targeting the reward system, typically employed in addictions. These results can be in line with the view of OCRDs as behavioral addictions, suggesting the implication of common circuits, such as the reward system, in the mechanisms at the basis of these disorders.