title: Cortical asymmetries in unaffected siblings of patients with obsessive-compulsive disorder.
abstract: Obsessive-compulsive disorder (OCD) is considered to be associated with atypical brain asymmetry. However, no study has examined the asymmetry in OCD from the perspective of cortical morphometry. This study is aimed to describe the characteristics of cortical asymmetry in OCD patients, and to investigate whether these features exist in their unaffected siblings - a vital step in identifying putative endophenotypes for OCD. A total of 48 subjects (16 OCD patients, 16 unaffected siblings, and 16 matched controls) were recruited who had complete magnetic resonance imaging scans. Left-right hemispheric asymmetries of cortical thickness were measured using a surface-based threshold-free cluster enhancement method. OCD patients and siblings both showed leftward asymmetries of cortical thickness in the anterior cingulate cortex (ACC), which showed a significant positive correlation with compulsive subscale scores. In addition, siblings and healthy controls showed significantly decreased leftward asymmetries in the orbitofrontal cortex (OFC), and the decreased leftward bias in the OFC was accompanied by lower scales on the Yale-Brown Obsessive-Compulsive Scale. To sum up, leftward asymmetries of cortical thickness in the ACC may represent an endophenotype of increased hereditary risk for OCD, while decreased leftward asymmetries of cortical thickness in the OFC may represent a protective factor.
authors.affiliation: Centre for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China; Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA.
authors.forename: Ziwen
authors.initials: Z
authors.lastname: Peng
authors.affiliation: Centre for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Centre for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Shi
authors.affiliation: Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Shi
authors.affiliation: Guangzhou Psychiatry Hospital, Guangzhou, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Raymond C K
authors.initials: RC
authors.lastname: Chan
authors.affiliation: Centre for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China; Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea. Electronic address: dinggang_shen@med.unc.edu.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D058068:Endophenotypes; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000473:pathology*; D017397:Prefrontal Cortex / Q000473:pathology*; D035781:Siblings
keywords: Cortical thickness; Endophenotype; Hemispheric asymmetry; Obsessive–compulsive disorder; Siblings