Study design and procedures
The study was preregistered (German clinical trials database: DRKS00003206, EUDAMED ID: CIV-11-05-000663) and conducted in three German centers (Cologne, Magdeburg, and Mannheim/Heidelberg) as a double-blind randomized controlled trial (RCT). After baseline assessment and randomization all participants received bilateral stereotactic implantation of DBS electrodes in the NAc with sub-clavicular implantation of the pulse generator (see Supplements for details on the surgical procedure and Supplementary Fig. 