Cyclic versus continuous deep brain stimulation in obsessive-compulsive disorder

INTERVENTION: Cyclic DBS (0,1 seconds ON, 0,2 seconds OFF) versus continuous DBS CONDITION: Obsessive‐compulsive disorder (OCD), Deep brain stimulation ; ; PRIMARY OUTCOME: Obsessive compulsive symptoms measured with the Yale‐Brown Obsessive‐Compulsive Scale (Y‐BOCS). SECONDARY OUTCOME: 1) Hamilton Anxiety Scale (HAS) and Hamilton Depression Rating Scale (HDRS) 2) battery power and battery usage between charging sessions 3) adverse events 4) subtests of the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess cognitive functions 5) resting state scalp EEG to assess amplitude, phase stability and cross‐frequency coupling of cortical theta ( 4 Hz), alpha ( 10 Hz) and gamma (>40 Hz) EEG oscillations; 6) EQ‐5D and WHOQOL to assess quality of life. INCLUSION CRITERIA: œ Subject has a primary diagnosis of OCD with DBS implantation performed in the previous years at the AMC. œ Subject has completed the period of optimization of stimulation settings. œ Subject has responded to DBS‐treatment, defined as an improvement of >25% in Y‐BOCS at last follow‐up compared to the pre‐surgical baseline. œ Subject has provided informed consent.