title: Larger putamen size in antipsychotic-naïve individuals with schizotypal personality disorder.
abstract: OBJECTIVE
  To (a) compare the size of the dorsal and ventral striatum (caudate and putamen) in a large sample of antipsychotic-naïve individuals with schizotypal personality disorder (SPD) and healthy control participants; (b) examine symptom correlates of striatal size in SPD.
  
  
  METHODS
  The left and right caudate and putamen were hand-traced on structural MRI at five dorsal to ventral slice levels in 76 SPD and 148 healthy control participants. A Group×Region (caudate, putamen)×Slice (1-5: ventral, 2, 3, 4, dorsal)×Hemisphere (left, right) mixed-model MANOVA was conducted on size relative to whole brain.
  
  
  RESULTS
  Primary results showed that compared with the controls, the SPD group showed (a) larger bilateral putamen size overall and this enlargement was more pronounced at the most ventral and dorsal levels; in contrast, there were no between-group differences in caudate volume; (b) larger bilateral size of the striatum ventrally, averaged across the caudate and putamen. Among the SPD group, larger striatal size ventrally, particularly in the left hemisphere was associated with less severe paranoid symptoms.
  
  
  CONCLUSIONS
  Striatal size is abnormal in SPD and resembles that of patients with schizophrenia who respond well to antipsychotic treatment. The results suggest that striatal size may be an important endophenotype to consider when developing new pharmacological treatments and when studying factors mitigating psychosis.
authors.affiliation: Mount Sinai School of Medicine, Department of Psychiatry, New York, NY, United States.
authors.forename: Eran
authors.initials: E
authors.lastname: Chemerinski
authors.forename: William
authors.initials: W
authors.lastname: Byne
authors.forename: Jeanine C
authors.initials: JC
authors.lastname: Kolaitis
authors.forename: Cathryn F
authors.initials: CF
authors.lastname: Glanton
authors.forename: Emily L
authors.initials: EL
authors.lastname: Canfield
authors.forename: Randall E
authors.initials: RE
authors.lastname: Newmark
authors.forename: M Mehmet
authors.initials: MM
authors.lastname: Haznedar
authors.forename: Vladan
authors.initials: V
authors.lastname: Novakovic
authors.forename: King-Wai
authors.initials: KW
authors.lastname: Chu
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Siever
authors.forename: Erin A
authors.initials: EA
authors.lastname: Hazlett
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003342:Corpus Striatum / Q000473:pathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011699:Putamen / Q000473:pathology*; D012569:Schizotypal Personality Disorder / Q000473:pathology*; D012720:Severity of Illness Index; D055815:Young Adult