title: Correlation of individual differences in schizotypal personality traits with amphetamine-induced dopamine release in striatal and extrastriatal brain regions.
abstract: OBJECTIVE
  Schizotypal personality traits are associated with schizophrenia spectrum disorders, and individuals with schizophrenia spectrum disorders demonstrate increased dopamine transmission in the striatum. The authors sought to determine whether individual differences in normal variation in schizotypal traits are correlated with dopamine transmission in the striatum and in extrastriatal brain regions.
  
  
  METHODS
  Sixty-three healthy volunteers with no history of psychiatric illness completed the Schizotypal Personality Questionnaire and underwent positron emission tomography imaging with [(18)F]fallypride at baseline and after administration of oral d-amphetamine (0.43 mg/kg). Dopamine release, quantified by subtracting each participant's d-amphetamine scan from his or her baseline scan, was correlated with Schizotypal Personality Questionnaire total and factor scores using region-of-interest and voxel-wise analyses.
  
  
  RESULTS
  Dopamine release in the striatum was positively correlated with overall schizotypal traits. The association was especially robust in the associative subdivision of the striatum. Voxel-wise analyses identified additional correlations between dopamine release and schizotypal traits in the left middle frontal gyrus and left supramarginal gyrus. Exploratory analyses of Schizotypal Personality Questionnaire factor scores revealed correlations between dopamine release and disorganized schizotypal traits in the striatum, thalamus, medial prefrontal cortex, temporal lobe, insula, and inferior frontal cortex.
  
  
  CONCLUSIONS
  The association between dopamine signaling and psychosis phenotypes extends to individual differences in normal variation in schizotypal traits and involves dopamine transmission in both striatal and extrastriatal brain regions. Amphetamine-induced dopamine release may be a useful endophenotype for investigating the genetic basis of schizophrenia spectrum disorders.
authors.affiliation: Psychiatric Neuroimaging Program, Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA. neil.woodward@vanderbilt.edu
authors.forename: Neil D
authors.initials: ND
authors.lastname: Woodward
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Cowan
authors.forename: Sohee
authors.initials: S
authors.lastname: Park
authors.forename: M Sib
authors.initials: MS
authors.lastname: Ansari
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Baldwin
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Mikisha
authors.initials: M
authors.lastname: Doop
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kessler
authors.forename: David H
authors.initials: DH
authors.lastname: Zald
mesh_terms: D000328:Adult; D000661:Amphetamine / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007206:Individuality; D008297:Male; D010555:Personality Inventory; D049268:Positron-Emission Tomography; D012569:Schizotypal Personality Disorder / Q000378:metabolism* / Q000523:psychology; D016037:Single-Blind Method; D013702:Temporal Lobe / Q000187:drug effects / Q000378:metabolism; D013788:Thalamus / Q000187:drug effects / Q000378:metabolism; D055815:Young Adult
chemical_list: D000661:Amphetamine; D004298:Dopamine