title: Cognitive functioning in psychiatric disorders following deep brain stimulation.
abstract: BACKGROUND
  Deep brain stimulation (DBS) is routinely used as a treatment for treatment-refractory Parkinson's disease and has recently been proposed for psychiatric disorders such as Tourette syndrome (TS), obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). Although cognitive deterioration has repeatedly been shown in patients with Parkinson's disease following DBS, the impact of DBS on cognitive functioning in psychiatric patients has not yet been reviewed.
  
  
  OBJECTIVE
  Reviewing the available literature on cognitive functioning following DBS in psychiatric patients.
  
  
  METHODS
  A systematic literature search in PubMed, EMBASE and Web of Science, last updated in September 2012, found 1470 papers. Abstracts were scrutinized and 26 studies examining cognitive functioning of psychiatric patients following DBS were included on basis of predetermined inclusion criteria.
  
  
  RESULTS
  Twenty-six studies reported cognitive functioning of 130 psychiatric patients following DBS (37 TS patients, 56 OCD patients, 28 MDD patients, 6 patients with Alzheimer's disease, and 3 patients with other disorders). None of the studies reported substantial cognitive decline following DBS. On the contrary, 13 studies reported cognitive improvement following DBS.
  
  
  CONCLUSIONS
  Preliminary results suggest that DBS in psychiatric disorders does not lead to cognitive decline. In selected cases cognitive functioning was improved following DBS. However, cognitive improvement cannot be conclusively attributed to DBS since studies are hampered by serious limitations. We discuss the outcomes in light of these limitations and offer suggestions for future work.
authors: Department of Psychiatry, Academic Medical Center, University of Amsterdam, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands. i.o.bergfeld@amc.nl
authors: Isidoor O
authors: IO
authors: Bergfeld
authors: Mariska
authors: M
authors: Mantione
authors: Mechteld L C
authors: ML
authors: Hoogendoorn
authors: Damiaan
authors: D
authors: Denys
mesh_terms: D003071:Cognition / Q000502:physiology*; D046690:Deep Brain Stimulation; D006801:Humans; D001523:Mental Disorders / Q000523:psychology* / Q000628:therapy; D016896:Treatment Outcome
keywords: Deep brain stimulation; Neuropsychological tests; Psychiatric diagnosis; Treatment outcome