title: Striatal amphetamine-induced dopamine release in patients with schizotypal personality disorder studied with single photon emission computed tomography and [123I]iodobenzamide.
abstract: BACKGROUND
  Previous imaging studies demonstrated that schizophrenia is associated with increased amphetamine-induced dopamine (DA) release in the striatum, most pronounced during episodes of illness exacerbation. Schizotypal personality disorder (SPD) is a schizophrenia spectrum disorder, genetically related to schizophrenia. The goal of this study was to investigate striatal DA function in patients with SPD.
  
  
  METHODS
  In our study, 13 SPD patients and 13 matched healthy control subjects underwent single photon emission computed tomography (SPECT) scan during bolus plus constant infusion of the D2/3 radiotracer [123I]iodobenzamide (IBZM). Striatal specific to nonspecific equilibrium partition coefficient (V(3)") was measured at baseline and following amphetamine administration (.3 mg/kg).
  
  
  RESULTS
  No significant differences were observed in baseline V(3)" between groups. Amphetamine induced a larger decrease in [123I]IBZM V(3)" in SPD patients (-12 +/- 5%) compared with control subjects (-7 +/- 5%, p =.03).
  
  
  CONCLUSIONS
  The reduction in [123I]IBZM V(3)" induced by amphetamine in SPD was similar to that observed in remitted schizophrenia patients (-10 +/- 9%, n = 17), but significantly lower than that observed during illness exacerbation (-24 +/- 13%, n = 17). This suggests that DA dysregulation in schizophrenia spectrum disorders might have a trait component, present in remitted patients with schizophrenia and in SPD, and a state component, associated with psychotic exacerbations but not SPD.
authors.affiliation: Department of Psychiatry, Columbia University, and New York State Psychiatric Institute, New York, 10032, USA.
authors.forename: Anissa
authors.initials: A
authors.lastname: Abi-Dargham
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Kegeles
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Zea-Ponce
authors.forename: Osama
authors.initials: O
authors.lastname: Mawlawi
authors.forename: Diana
authors.initials: D
authors.lastname: Martinez
authors.forename: Vivian
authors.initials: V
authors.lastname: Mitropoulou
authors.forename: Karen
authors.initials: K
authors.lastname: O'Flynn
authors.forename: Harold W
authors.initials: HW
authors.lastname: Koenigsberg
authors.forename: Ronald
authors.initials: R
authors.lastname: Van Heertum
authors.forename: Thomas
authors.initials: T
authors.lastname: Cooper
authors.forename: Marc
authors.initials: M
authors.lastname: Laruelle
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Siever
mesh_terms: D000328:Adult; D000661:Amphetamine / Q000097:blood / Q000494:pharmacology*; D000704:Analysis of Variance; D001549:Benzamides; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D012557:Schizoid Personality Disorder / Q000000981:diagnostic imaging / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D001549:Benzamides; D000697:Central Nervous System Stimulants; D018492:Dopamine Antagonists; D007457:Iodine Radioisotopes; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D000661:Amphetamine; D004298:Dopamine