title: Impaired cognitive flexibility and motor inhibition in unaffected first-degree relatives of patients with obsessive-compulsive disorder.
abstract: OBJECTIVE
  Obsessive-compulsive disorder (OCD) is highly heritable. Attempts to delineate precise genetic contributions have met with limited success. There is an ongoing search for intermediate cognitive brain markers (endophenotypes) that may help clarify genetic contributions. The aim was to assess inhibitory control processes in unaffected first-degree relatives of OCD patients for the first time with objective tests.
  
  
  METHODS
  The Intradimensional/Extradimensional Shift, Stop-Signal, and Cambridge Gamble tasks were administered to 20 unaffected first-degree relatives, 20 OCD patient probands with washing/checking symptoms, and 20 healthy matched comparison subjects without a family history of OCD.
  
  
  RESULTS
  Unaffected first-degree relatives and OCD patient probands showed cognitive inflexibility (extradimensional set shifting) and motor impulsivity (stop-signal reaction times). Decision making (Cambridge Gamble task) was intact.
  
  
  CONCLUSIONS
  Deficits in cognitive flexibility and motor inhibition may represent cognitive endophenotypes for OCD. Such measures will play a key role in understanding genotype/phenotype associations for OCD and related spectrum conditions.
authors.affiliation: Department of Psychiatry, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Box 189, Cambridge, CB2 2QQ UK. src33@cam.ac.uk
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Chamberlain
authors.forename: Naomi A
authors.initials: NA
authors.lastname: Fineberg
authors.forename: Lara A
authors.initials: LA
authors.lastname: Menzies
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Blackwell
authors.forename: Edward T
authors.initials: ET
authors.lastname: Bullmore
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Robbins
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Sahakian
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis* / Q000235:genetics; D003192:Compulsive Behavior / Q000175:diagnosis / Q000235:genetics; D003657:Decision Making; D005192:Family Health; D005260:Female; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D010375:Pedigree; D010641:Phenotype; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology*
chemical_list: D005819:Genetic Markers