Clinical Research Directory

1.Inclusion Criteria for Patient: (1) Age between 12 and 55 years. (2) A primary diagnosis of OCD according to DSM-5 criteria. (3) Excoriation (Skin-Picking) Disorder (SPD) according to DSM-5 criteria. (4) Met criteria for treatment resistance, defined as: (a) A Y-BOCS score ≥ 16. (b) A history of inadequate response (\<25% reduction in Y-BOCS score) to at least two different serotonin reuptake inhibitors (SSRIs) at an adequate dose for at least 12 weeks each. 1.2 Inclusion Criteria for Healthy Controls: (1) Age and sex-matched to the patient group. (2) No personal history of any psychiatric disorder. 1.3 Exclusion Criteria for All Participants: (1) Presence of any contraindications to 3T MRI scanning (e.g., metallic implants, claustrophobia). (2) Current (within the past 6 months) diagnosis of a substance use disorder. (3) Significant or unstable neurological illness (e.g., epilepsy, multiple sclerosis, brain tumor). (4) History of significant head trauma or neurosurgery. 1.4 Additional Exclusion Criteria for Patients with TR-OCD: (1) Current or lifetime diagnosis of a primary psychotic disorder (e.g., schizophrenia), bipolar I/II disorder, or intellectual disability. (2) Any contraindication to the use of N-acetylcysteine.