Deep brain stimulation (DBS) is an effective treatment option for patients with refractory obsessivecompulsive disorder (OCD). However, clinical experience with DBS for OCD remains limited. The authors examined the tolerability and effectiveness of DBS in an open study of patients with refractory OCD.Methods: Seventy consecutive patients, including 16 patients from a previous trial, received bilateral DBS of the ventral anterior limb of the internal capsule (vALIC) between April 2005 and October 2017 and were followed for 12 months. Primary effectiveness was assessed by the change in scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline until the 12-month follow-up. Response was defined by a $35% decrease in Y-BOCS score, partial response was defined by a 25%234% decrease, and nonresponse was defined by a ,25% decrease. Secondary effectiveness measures were the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D).Results: Y-BOCS, HAM-A, and HAM-D scores all decreased significantly during the first 12 months of DBS. Twelve months of DBS resulted in a mean Y-BOCS score decrease of 13.5 points (SD=9.4) (40% reduction; effect size=1.5). HAM-A scores decreased by 13.4 points (SD=9.7) (55%; effect size= 1.4), and HAM-D scores decreased by 11.2 points (SD= 8.8) (54%; effect size=1.3). At the 12-month follow-up, 36 of the 70 patients were categorized as responders (52%), 12 patients as partial responders (17%), and 22 patients as nonresponders (31%). Adverse events included transient symptoms of hypomania, agitation, impulsivity, and sleeping disorders.Conclusions: These results confirm the effectiveness and safety of DBS of the vALIC for patients with treatmentrefractory OCD in a regular clinical setting.

Deep brain stimulation (DBS) is a last-resort treatment for neurological and psychiatric disorders that are refractory to standard treatment. Over the last decades, the progress of DBS in psychiatry has been slower than in neurology, in part owing to the heterogenic symptomatology and complex neuroanatomy of psychiatric disorders. However, for obsessive-compulsive disorder (OCD) DBS is now an accepted treatment. This study first reviews clinical outcomes and mechanisms of DBS for OCD, and then discusses these results in an overview of current and future psychiatric applications, including DBS for mood disorders, Tourette's syndrome, addiction, anorexia nervosa, autism, schizophrenia, and anxiety disorders. In addition, it will focus on novel techniques that may enhance the application of DBS in psychiatry.ARTICLE HISTORY

Objectives Deep brain stimulation (DBS) is an innovative and effective treatment for patients with therapy‐refractory obsessive–compulsive disorder (OCD). DBS offers unique opportunities for personalized care, but no guidelines on how to choose effective and safe stimulation parameters in patients with OCD are available. Our group gained relevant practical knowledge on DBS optimization by treating more than 80 OCD patients since 2005, the world's largest cohort. The article's objective is to share this experience. Materials and Methods We provide guiding principles for optimizing DBS stimulation parameters in OCD and discuss the neurobiological and clinical basis. Results Adjustments in stimulation parameters are performed in a fixed order. First, electrode contact activation is determined by the position of the electrodes on postoperative imaging. Second, voltage and pulse width are increased stepwise, enlarging both the chance of symptom reduction and of inducing side effects. Clinical evaluation of adjustments in stimulation parameters needs to take into account: 1) the particular temporal sequence in which the various OCD symptoms and DBS side‐effects change; 2) the lack of robust response predictors; 3) the limited sensitivity of the Yale‐Brown Obsessive–Compulsive Scale to assess DBS‐induced changes in OCD symptoms; and 4) a patient's fitness for additional cognitive‐behavioral therapy (CBT). Conclusions Decision‐making in stimulation parameter optimization needs to be sensitive to the particular time‐courses on which various symptoms and side effects change.