title: Clinical correlates of nucleus accumbens volume in drug-naive, adult patients with obsessive-compulsive disorder.
abstract: BACKGROUND
  Reward-processing deficits have been demonstrated in obsessive-compulsive disorder (OCD) and this has been linked to ventral striatal abnormalities. However, volumetric abnormalities of the nucleus accumbens (NAcc), a key structure in the reward pathway, have not been examined in OCD. We report on the volumetric abnormalities of NAcc and its correlation with illness severity in drug-naïve, adult patients with OCD.
  
  
  METHODS
  In this cross-sectional study of case-control design, the magnetic resonance imaging (MRI) 1.5-T (1-mm) volume of NAcc was measured using 3D Slicer software in drug-naïve OCD patients (n = 44) and age, sex and handedness-matched healthy controls (HCs) (n = 36) using a valid and reliable method. OCD symptoms were assessed using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) Symptom checklist and severity and the Clinical Global Impression-Severity (CGI-S) scale.
  
  
  RESULTS
  There was no significant difference in NAcc volumes on either side between OCD patients and HCs (F = 3.45, p = 0.07). However, there was significant negative correlation between the right NAcc volume and Y-BOCS compulsion score (r = -0.48, p = 0.001).
  
  
  CONCLUSIONS
  Study observations suggest involvement of the NAcc in the pathogenesis of OCD, indicating potential reward-processing deficits. Correlation between the right NAcc volume deficit and severity of compulsions offers further support for this region as a candidate for deep brain stimulation treatment in OCD.
authors.affiliation: Obsessive Compulsive Disorder Clinic & Translational Psychiatry Lab, Neurobiology Research Center at National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: Janardhanan C
authors.initials: JC
authors.lastname: Narayanaswamy
authors.forename: Dania
authors.initials: D
authors.lastname: Jose
authors.forename: Sunil
authors.initials: S
authors.lastname: Kalmady
authors.forename: Ganesan
authors.initials: G
authors.lastname: Venkatasubramanian
authors.forename: Y C Janardhan
authors.initials: YC
authors.lastname: Reddy
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009714:Nucleus Accumbens / Q000473:pathology*; D009771:Obsessive-Compulsive Disorder / Q000473:pathology*; D009929:Organ Size; D012720:Severity of Illness Index
keywords: Nucleus accumbens; obsessive compulsive disorder; reward pathway