title: Dopaminergic function in the psychosis spectrum: an [18F]-DOPA imaging study in healthy individuals with auditory hallucinations.
abstract: BACKGROUND
  The psychosis phenotype appears to exist in the population as a continuum, but it is not clear if subclinical psychotic symptoms and psychotic disorders share the same neurobiology. We investigated whether the dopaminergic dysfunction seen in psychotic disorders is also present in healthy, well-functioning people with hallucinations.
  
  
  METHODS
  We compared dopamine synthesis capacity (using 6-[(18)F]fluoro-L-DOPA [[(18)F]-DOPA] positron emission tomography imaging) in 16 healthy individuals with frequent persistent auditory verbal hallucinations (hallucinating group) with that in 16 matched controls.
  
  
  RESULTS
  There was no significant difference in dopamine synthesis capacity in the striatum, or its functional subdivisions, between groups and no relationship between subclinical psychotic symptom severity or schizotypal traits and dopamine synthesis capacity in the hallucinating group.
  
  
  CONCLUSIONS
  Altered dopamine synthesis capacity is unlikely to underlie subclinical hallucinations, suggesting that although there may be a phenomenological psychosis continuum, there are distinctions at the neurobiological level.
authors.affiliation: Psychiatric Imaging Group, MRC Clinical Science Centre, Imperial College Hammersmith Campus, London, UK. oliver.howes@imperial.ac.uk
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Howes
authors.forename: Paul
authors.initials: P
authors.lastname: Shotbolt
authors.forename: Michael
authors.initials: M
authors.lastname: Bloomfield
authors.forename: Kirstin
authors.initials: K
authors.lastname: Daalman
authors.forename: Arsime
authors.initials: A
authors.lastname: Demjaha
authors.forename: Kelly M J
authors.initials: KM
authors.lastname: Diederen
authors.forename: Kemal
authors.initials: K
authors.lastname: Ibrahim
authors.forename: Euitae
authors.initials: E
authors.lastname: Kim
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
authors.forename: René S
authors.initials: RS
authors.lastname: Kahn
authors.forename: Iris E
authors.initials: IE
authors.lastname: Sommer
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D016022:Case-Control Studies; D004298:Dopamine / Q000031:analogs & derivatives / Q000096:biosynthesis*; D005260:Female; D005462:Fluorine Radioisotopes; D006212:Hallucinations / Q000000981:diagnostic imaging* / Q000378:metabolism; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D017072:Neostriatum / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography
chemical_list: D005462:Fluorine Radioisotopes; C029253:6-fluorodopamine; D004298:Dopamine