title: Scrupulosity and contamination OCD are not associated with deficits in response inhibition.
abstract: OBJECTIVE
  Prior research has indicated a number of neuropsychological deficits in patients with OCD consistent with the cortico-striato-thalamo-cortical model of the disorder. Response inhibition (RI), defined as the inability to inhibit a prepotent response, has been identified as a possible candidate endophenotype for OCD. However, the results from previous studies of RI in OCD patients have been mixed, suggesting the possibility that some OCD dimensions may be associated with deficits in RI while others may not. The present study aimed to examine RI using a Go/No-Go (GNG) task in two OCD symptom dimensions, one of which, scrupulosity, has never been subject to neuropsychological investigation.
  
  
  METHODS
  A total of 63 individuals, consisting of scrupulous OCD (n = 26), contamination OCD (n = 18) and non-psychiatric controls (n = 19) completed study measures. Controlling for depression symptoms, no significant performance differences were found between the groups on the GNG test, indicating no deficits in RI among contamination or scrupulous OCD.
  
  
  RESULTS
  Results are consistent with several prior studies of RI in OCD that found no differences as compared to non-psychiatric controls, especially on GNG tests, and with more recent suggestions that RI may not constitute a clinical significant impaired domain in OCD.
  
  
  CONCLUSIONS
  Limitations included a primarily highly educated and Caucasian sample.
  
  
  CONCLUSIONS
  Additional conclusions include careful consideration of the RI measures selected for future studies, as well as the need for further investigation into the neuropsychological and neurobiological nature of scrupulous OCD.
authors.affiliation: Massachusetts General Hospital & Harvard Medical School, USA. Electronic address: jrasmussen@mgh.harvard.edu.
authors.forename: Jessica
authors.initials: J
authors.lastname: Rasmussen
authors.affiliation: Nova Southeastern University, USA.
authors.forename: Jedidiah
authors.initials: J
authors.lastname: Siev
authors.affiliation: Massachusetts General Hospital & Harvard Medical School, USA; Texas State University, USA.
authors.forename: Amitai
authors.initials: A
authors.lastname: Abramovitch
authors.affiliation: Massachusetts General Hospital & Harvard Medical School, USA.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wilhelm
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D009014:Morals; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology*; D010698:Phobic Disorders / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology*
keywords: Obsessive-compulsive disorder; Response inhibition; Scrupulosity