title: Functional and structural neural indices of risk aversion in obsessive-compulsive disorder (OCD).
abstract: Obsessive-compulsive disorder (OCD) patients suffer from risk aversion, which may be mediated by their exaggerated response to threat and diminished response to reward. In this study, 13 OCD patients and 13 healthy matched controls underwent functional magnetic resonance imaging (fMRI) while playing an interactive risky choice game encompassing distinct intervals of threat and reward; as well as anatomical diffusion tensor imaging (DTI). Compared to healthy controls OCD patients were reluctant to make risky choices during the game. Furthermore, they displayed higher amygdala activation to threat; lower nucleus accumbens (Nacc) activation to reward and reduced functional connectivity of the amygdala and Nacc to two frontal regions, the orbito-frontal cortex (OFC) and the dorsal anterior cingulate cortex (dACC), respectively. OCD patients also displayed reduced structural integrity in clusters within the uncinate and cingulum fiber tracts. Finally, these deficits in limbic-frontal connectivity pathways, both at the functional and structural level, were associated with severity of OCD symptoms, as well as with each other. Our results thus suggest that risk aversion in OCD is mediated by abnormal limbic responses to threatening and rewarding stimuli, as well as by deficient functional and structural limbic-frontal connectivity. Such deficiency characterization may aid in identifying neural predictors for treatment response and localizing individual targets for direct neural intervention treatments.
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. roee@fmri-tlv.org
authors.forename: Roee
authors.initials: R
authors.lastname: Admon
authors.forename: Maya
authors.initials: M
authors.lastname: Bleich-Cohen
authors.forename: Ronit
authors.initials: R
authors.lastname: Weizmant
authors.forename: Michael
authors.initials: M
authors.lastname: Poyurovsky
authors.forename: Sarit
authors.initials: S
authors.lastname: Faragian
authors.forename: Talma
authors.initials: T
authors.lastname: Hendler
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology; D001143:Arousal / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D005715:Gambling / Q000503:physiopathology / Q000523:psychology; D006179:Gyrus Cinguli / Q000503:physiopathology; D040261:Harm Reduction / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009714:Nucleus Accumbens / Q000503:physiopathology; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D011237:Predictive Value of Tests; D012309:Risk-Taking; D055815:Young Adult