title: Cortical thickness, surface area, and folding alterations in male youths with conduct disorder and varying levels of callous-unemotional traits.
abstract: OBJECTIVE
  Previous studies have reported changes in gray matter volume in youths with conduct disorder (CD), although these differences are difficult to interpret as they may have been driven by alterations in cortical thickness, surface area (SA), or folding. The objective of this study was to use surface-based morphometry (SBM) methods to compare male youths with CD and age and sex-matched healthy controls (HCs) in cortical thickness, SA, and folding. We also tested for structural differences between the childhood-onset and adolescence-onset subtypes of CD and performed regression analyses to assess for relationships between CD symptoms and callous-unemotional (CU) traits and SBM-derived measures.
  
  
  METHODS
  We acquired structural neuroimaging data from 20 HCs and 36 CD participants (18 with childhood-onset CD and 18 with adolescence-onset CD) and analyzed the data using FreeSurfer.
  
  
  RESULTS
  Relative to HCs, youths with CD showed reduced cortical thickness in the superior temporal gyrus, reduced SA in the orbitofrontal cortex (OFC), and increased cortical folding in the insula. There were no significant differences between the childhood-onset and adolescence-onset CD subgroups in cortical thickness or SA, but several frontal and temporal regions showed increased cortical folding in childhood-onset relative to adolescence-onset CD participants. Both CD subgroups also showed increased cortical folding relative to HCs. CD symptoms were negatively correlated with OFC SA whereas CU traits were positively correlated with insula folding.
  
  
  CONCLUSIONS
  Cortical thinning in the superior temporal gyrus may contribute to the social cognitive impairments displayed by youths with CD, whereas reduced OFC SA may lead to impairments in emotion regulation and reward processing in youths with CD. The increased cortical folding observed in the insula may reflect a maturational delay in this region and could mediate the link between CU traits and empathy deficits. Altered cortical folding was observed in childhood-onset and adolescence-onset forms of CD.
authors.affiliation: Academic Unit of Psychology, University of Southampton, Southampton, UK ; Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors.forename: Graeme
authors.initials: G
authors.lastname: Fairchild
authors.affiliation: Department of Biomedicine and Prevention, University of Rome, Rome , Italy ; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, USA ; Harvard Medical School, Boston, MA, USA.
authors.forename: Nicola
authors.initials: N
authors.lastname: Toschi
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, UK ; Department of Psychology, Columbia University, New York, NY, USA.
authors.forename: Cindy C
authors.initials: CC
authors.lastname: Hagan
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Goodyer
authors.affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Calder
authors.affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK ; Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy ; Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Passamonti
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000987:Antisocial Personality Disorder / Q000473:pathology*; D002540:Cerebral Cortex / Q000254:growth & development / Q000473:pathology*; D019955:Conduct Disorder / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult
keywords: Callous–unemotional traits; Conduct disorder; Developmental taxonomic theory; Surface based morphometry