title: Obsessive-compulsive symptoms and related sex differences in brain structure: an MRI study in Dutch twins.
abstract: Neuroimaging studies have indicated abnormalities in cortico-striato-thalamo-cortical circuits in obsessive-compulsive disorder patients, but results have not been consistent. Since there are significant sex differences in human brain anatomy and obsessive-compulsive symptomatology and its developmental trajectories tend to be distinct in males and females, we investigated whether sex is a potential source of heterogeneity in neuroimaging studies on obsessive-compulsive symptoms. We selected male and female twin pairs who were concordant for scoring either high or low for obsessive-compulsive symptoms and a group of discordant pairs where one twin scored high and the co-twin scored low. The design included 24 opposite-sex twin pairs. Magnetic resonance imaging scans of 31 males scoring high for obsessive-compulsive symptoms, 41 low-scoring males, 58 high-scoring females, and 73 low-scoring females were analyzed and the interaction of obsessive-compulsive symptoms by sex on gray matter volume was assessed using voxel-based morphometry. An obsessive-compulsive symptom by sex interaction was observed for the left middle temporal gyrus, the right middle temporal gyrus, and the right precuneus. These interactions acted to reduce or hide a main effect in our study and illustrate the importance of taking sex into account when investigating the neurobiology of obsessive-compulsive symptoms.
authors.affiliation: Department of Biological Psychology, VU University, Amsterdam, The Netherlands. a.den.braber@vu.nl
authors.forename: Anouk
authors.initials: A
authors.lastname: den Braber
authors.forename: Eco J C
authors.initials: EJ
authors.lastname: de Geus
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: Dennis
authors.initials: D
authors.lastname: van 't Ent
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004200:Diseases in Twins / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D012737:Sex Factors; D035781:Siblings; D014429:Twins, Dizygotic / Q000235:genetics* / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics* / Q000523:psychology; D055815:Young Adult