Background: Obsessive-compulsive disorder (OCD) is a common neurotic disorder, In 2018 Application of repetitive transcranial magnetic stimulation (rTMS) for treating obsessive-compulsive disorder (OCD) has been approved by the Food and Drug Administration (28), since 2020 different methods has been tested, this study was designed to evaluate the effectiveness of adjunctive low frequency repetitive transcranial magnetic stimulation over the left dorsolateral prefrontal cortex in refractory to treatment patients suffering from obsessive compulsive disorder (OCD)
Methods: This clinical trial was performed on 30 patients with OCD referred from the psychiatry clinic of 22 Bahman Hospital in Qazvin province from 2018 to 2020. Patients were randomly assigned to two groups. Intervention group received rTMS treatment at 1 Hz for 20 min (1200 (pulses / day) over the left DLPFC region as adjunctive to their medical treatment for 3 times a week and for 5 weeks while the control group received only sham condition in addition to their medical treatment. All the patients filled out the Yale Brown Questionnaire (YBOCS) Before the study, after sessions 5 and 10 during treatment, at the end of the treatment and 3 to 6 months after the treatment. The results were compared between the two groups using SPSS software version 16.
Results: The mean score of post-intervention Yale Brown score was significantly lower in the intervention group. (P <0.05), it was also significant by gender (females), marital status ,taking antipsychotic agents in addition to the serotonergic agents and with more treatment sessions, within 3 to 6 months after intervention.
Conclusion: adjunctive low frequency (1 Hz)rtms over the left DLPFC can be effective in reducing Yale Brown score in refractory to treatment patients suffering from OCD after 15 sessions. Gender, treatment sessions, usage of antipsychotic agents as adjuvant with standard treatment regiments, and marital status were identified as predictors for response to adjunctive rTMS therapy.