TMS for Exposure Therapy Resistant OCD

Inclusion Criteria: * OCD as current primary diagnosis * Age 18 and older * Yale-Brown Obsessive-Compulsive Scale (YBOCS) score of 16 or higher. * Insufficient response to state-of-the art exposure therapy with response prevention (ERP) and/or drop-out from ERP due to extreme anxiety/avoidance * The following comorbid disorders are allowed (as long as OCD is the current primary diagnosis): depression, other anxiety disorders, ADHD, tic/Tourette's disorder, eating disorders, personality disorders, autism spectrum disorder (when this does not dominate the clinical profile, i.e. is not main diagnosis). * Commitment to actively undergo intensive exposure therapy (both supervised during ERP sessions, as well as unsupervised at home) * Unmedicated (for at least 8 weeks) or stable dosage of psychotropic medication (for at least 8 weeks), involving serotonergic antidepressants (SSRI, SNRI, clomipramine). Other psychotropic medication that is allowed (provided dosage is stably established for at least 8 weeks): methylphenidate, mood stabilizers, antipsychotic drugs * Ability to participate in frequent treatment sessions (4 days/week, for 5 (or 6, or 7) weeks) at one of the 5 sites nearest to their home and/or work * Ability to participate in pre-treatment MRI session (for neuronavigation) at one of the 3 academic sites nearest to their home and/or work * Capacity for providing informed consent Exclusion Criteria: * OCD patients with hoarding as main symptom dimension * The following comorbid disorders (current diagnosis) are not allowed: psychotic disorders, bipolar disorder, autism spectrum disorder (when this dominates the clinical profile, i.e. is diagnosed as main disorder), substance use disorder * Active suicidal thoughts and intent to act on it * Chronic use of benzodiazepines is not allowed * Cochlear implant * (History of) epilepsy * Pregnancy * Extreme claustrophobia or metallic objects in or on the body, preventing from participation in MRI session * Space-occupying lesion on MRI * Previous rTMS treatment (for blinding reasons)