title: A meta-analysis of sex differences in human brain structure.
abstract: The prevalence, age of onset, and symptomatology of many neuropsychiatric conditions differ between males and females. To understand the causes and consequences of sex differences it is important to establish where they occur in the human brain. We report the first meta-analysis of typical sex differences on global brain volume, a descriptive account of the breakdown of studies of each compartmental volume by six age categories, and whole-brain voxel-wise meta-analyses on brain volume and density. Gaussian-process regression coordinate-based meta-analysis was used to examine sex differences in voxel-based regional volume and density. On average, males have larger total brain volumes than females. Examination of the breakdown of studies providing total volumes by age categories indicated a bias towards the 18-59 year-old category. Regional sex differences in volume and tissue density include the amygdala, hippocampus and insula, areas known to be implicated in sex-biased neuropsychiatric conditions. Together, these results suggest candidate regions for investigating the asymmetric effect that sex has on the developing brain, and for understanding sex-biased neurological and psychiatric conditions.
authors.affiliation: Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge CB2 8AH, United Kingdom. Electronic address: ar560@cam.ac.uk.
authors.forename: Amber N V
authors.initials: AN
authors.lastname: Ruigrok
authors.affiliation: Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Salimi-Khorshidi
authors.affiliation: Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge CB2 8AH, United Kingdom; Department of Psychiatry, College of Medicine, National Taiwan University, No. 1 Jen-Ai Road Section 1, Taipei 10051, Taiwan.
authors.forename: Meng-Chuan
authors.initials: MC
authors.lastname: Lai
authors.affiliation: Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge CB2 8AH, United Kingdom; Cambridgeshire and Peterborough NHS Foundation Trust, Elizabeth House, Fulbourn Hospital, Cambridge CB21 5EF, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Baron-Cohen
authors.affiliation: Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge CB2 8AH, United Kingdom; Department of Psychology, University of Cyprus, P.O. Box 20537, CY 1678 Nicosia, Cyprus.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Lombardo
authors.affiliation: Brain Mapping Unit, School of Clinical Medicine, University of Cambridge, Herchel Smith Building, Robinson Way, Cambridge CB2 0SP, United Kingdom; Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, United Kingdom.
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Tait
authors.affiliation: Cambridgeshire and Peterborough NHS Foundation Trust, Elizabeth House, Fulbourn Hospital, Cambridge CB21 5EF, United Kingdom; Brain Mapping Unit, School of Clinical Medicine, University of Cambridge, Herchel Smith Building, Robinson Way, Cambridge CB2 0SP, United Kingdom; Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Suckling
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D055815:Young Adult
keywords: Brain; Gaussian-process regression (GPR); Meta-analysis; Sex differences; Volume; Voxel-based morphometry