Objective: Establishing efficacy and safety of the electrodes and implantable pulse generators (IPGs), which are used for deep brain stimulation (DBS) in patients with obsessive-compulsive disorder (OCD).
Study design: Prospective cohort study.
Inclusion criteria: 1) OCD according to DSM-5 criteria; 2) At least one of the following conditions is met: a) Y-BOCS score ≥ 25, b) Y-BOCS ≥ 13 in case of solely obsessions or compulsions, or c) Suffering from obsessions or compulsions for at least 8 hours a day (i.e. a score of 4 on item 1 or item 6 of the Y-BOCS); 3) Treatment refractoriness as agreed upon by a multidisciplinary team of experts; 4) age must be 18 years or older; 5) mentally capable to understand the consequences of the procedure and make his or her own choice without coercion; 6) written informed consent.
Exclusion criteria: 1) Primary diagnosis in psychotic spectrum; 2) Unstable multiple sclerosis (MS); 3) Acute brain damage (e.g. recent hemorrhage or stroke); 4) General contraindications to have surgery.
Sample size: This study concerns a registration study to monitor efficacy and safety until OCD is added as an indication to the CE mark of the concerning medical devices. Therefore, all eligible patients with OCD for deep brain stimulation are included. A sample size calculation is not applicable.
Intervention (if applicable): DBS targeted to the capsular area around the striatum. DBS consists of two phases: neurosurgical implantation of electrodes and an IPG, followed by optimization of electrical parameters of the pulses given off by the electrodes (e.g. voltage, frequency or pulse width).
Primary study outcome: Change in Y-BOCS score compared to baseline, evaluated on a yearly basis.
Follow-up: The first year of the treatment, the patient is measured 5 times: before DBS surgery (T0), after surgery with stimulation still off (T1), after optimizing DBS settings (T2), after addition of cognitive behavioral therapy (T3), and one year after DBS surgery (T4). After the first year, the patient is followed-up once a year in clinical practice and will be asked to participate in a database study (LTx, W20_536: DEBASE study). The study ends after OCD is added as an indication to the CE mark of the concerning devices.