Obsessive-compulsive disorder (OCD) is characterized by impaired sensorimotor gating, as measured using prepulse inhibition (PPI). This effect may be related to abnormalities in the serotonin (5-HT) system. 5-HT1B agonists can impair PPI, produce OCD-like behaviors in animals, and exacerbate OCD symptoms in humans. We measured 5-HT1B receptor availability using 11C-P943 positron emission tomography (PET) in unmedicated, non-depressed OCD patients (n=12) and matched healthy controls (HC; n=12). Usable PPI data were obtained from 20 of these subjects (10 from each group). There were no significant main effects of OCD diagnosis on 5-HT1B receptor availability (11C-P943 BPND); however, the relationship between PPI and 11C-P943 BPND differed dramatically and significantly between groups. 5-HT1B receptor availability in the basal ganglia and thalamus correlated positively with PPI in controls; these correlations were lost or even reversed in the OCD group. In cortical regions there were no significant correlations with PPI in controls, but widespread positive correlations in OCD patients. Positive correlations between 5-HT1B receptor availability and PPI were consistent across diagnostic groups only in two structures, the orbitofrontal cortex and the amygdala. Differential associations of 5-HT1B receptor availability with PPI in patients suggest functionally important alterations in the serotonergic regulation of cortical/subcortical balance in OCD.
|Number of pages
|Journal of Affective Disorders
|Published - May 15 2016
Bibliographical noteFunding Information:
The authors gratefully acknowledge the staff of the Yale PET Center, and Brian Pittman, MS, for biostatistical support. This work was supported by NIH grants R21MH090555 (CP), K08MH081190 (CP), T32MH062994 (TA; M. Bell, PI), and CTSA Grant no. UL1TR000142 from the National Center for Advancing Translational Science (NCATS). Its content is solely the responsibility of the authors and does not necessarily reflect the official view of NIH. Additional support came from the State of Connecticut through its support of the Ribicoff Research Facilities at the Connecticut Mental Health Center. The authors have no real or apparent conflict of interest of relevance to this work.
© 2016 Elsevier B.V. All rights reserved.
ASJC Scopus subject areas
- Clinical Psychology
- Psychiatry and Mental health