title: Distinguishing between major depressive disorder and obsessive-compulsive disorder in children by measuring regional cortical thickness.
abstract: BACKGROUND
  Cortical abnormalities have been noted in previous studies of major depressive disorder (MDD).
  
  
  OBJECTIVE
  To hypothesize differences in regional cortical thickness among children with MDD, children with obsessive-compulsive disorder (OCD), and healthy controls.
  
  
  METHODS
  Cross-sectional study of groups.
  
  
  METHODS
  Children's Hospital of Michigan in Detroit.
  
  
  METHODS
  A total of 24 psychotropic drug-naive pediatric patients with MDD (9 boys and 15 girls), 24 psychotropic drug-naive pediatric outpatients with OCD (8 boys and 16 girls), and 30 healthy controls (10 boys and 20 girls).
  
  
  METHODS
  Magnetic resonance imaging.
  
  
  METHODS
  Cortical thickness.
  
  
  RESULTS
  In the right hemisphere of the brain, the pericalcarine gyrus was thinner in patients with MDD than in outpatients with OCD (P = .002) or healthy controls (P = .04), the postcentral gyrus was thinner in patients with MDD than in outpatients with OCD (P = .002) or healthy controls (P = .02), and the superior parietal gyrus was thinner in patients with MDD than in outpatients with OCD (P = .008) or healthy controls (P = .03). The outpatients with OCD and the healthy controls did not differ in these regions of the brain. The temporal pole was thicker in patients with MDD than in outpatients with OCD (P < .001) or healthy controls (P = .01), both of which groups did not differ in temporal pole thickness. The cuneus was thinner in patients with MDD than in outpatients with OCD (P = .008), but it did not differ from that in healthy controls. In the left hemisphere, the supramarginal gyrus was thinner in both patients with MDD (P = .04) and outpatients with OCD (P = .01) than in healthy controls, and the temporal pole was thicker in patients with MDD than in both healthy controls and outpatients with OCD (P < .001).
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to explore cortical thickness in pediatric patients with MDD. Although differences in some regions of the brain would be expected given neurobiological models of MDD, our study highlights some unexpected regions (ie, supramarginal and superior parietal gyri) that merit further investigation. These results underscore the need to expand exploration beyond the frontal-limbic circuit.
authors.affiliation: Department of Psychiatry and Behavioral Neurosciences, Wayne State University, and Children’s Hospital of Michigan, Detroit, Michigan, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Fallucca
authors.forename: Frank P
authors.initials: FP
authors.lastname: MacMaster
authors.forename: Joseph
authors.initials: J
authors.lastname: Haddad
authors.forename: Phillip
authors.initials: P
authors.lastname: Easter
authors.forename: Rachel
authors.initials: R
authors.lastname: Dick
authors.forename: Geoffrey
authors.initials: G
authors.lastname: May
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Stanley
authors.forename: Carrie
authors.initials: C
authors.lastname: Rix
authors.forename: David R
authors.initials: DR
authors.lastname: Rosenberg
mesh_terms: D000293:Adolescent; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology*; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral / Q000235:genetics / Q000502:physiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D009929:Organ Size / Q000502:physiology