Striatal amphetamine-induced dopamine release in patients with schizotypal personality disorder studied with single photon emission computed tomography and [123I]iodobenzamide

Biol Psychiatry. 2004 May 15;55(10):1001-6. doi: 10.1016/j.biopsych.2004.01.018.

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Amphetamine / blood
  • Amphetamine / pharmacology*
  • Analysis of Variance
  • Benzamides*
  • Case-Control Studies
  • Central Nervous System Stimulants / pharmacology
  • Corpus Striatum / metabolism*
  • Dopamine / metabolism*
  • Dopamine Antagonists
  • Female
  • Humans
  • Iodine Radioisotopes
  • Male
  • Middle Aged
  • Psychiatric Status Rating Scales
  • Pyrrolidines*
  • Receptors, Dopamine D2 / metabolism
  • Schizoid Personality Disorder / diagnostic imaging
  • Schizoid Personality Disorder / metabolism*
  • Tomography, Emission-Computed, Single-Photon

Substances

  • Benzamides
  • Central Nervous System Stimulants
  • Dopamine Antagonists
  • Iodine Radioisotopes
  • Pyrrolidines
  • Receptors, Dopamine D2
  • 3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide
  • Amphetamine
  • Dopamine