Striatal amphetamine-induced dopamine release in patients with schizotypal personality disorder studied with single photon emission computed tomography and [123I]iodobenzamide.
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.
Abi-Dargham
Anissa
A
Department of Psychiatry, Columbia University, and New York State Psychiatric Institute, New York, 10032, USA.
Kegeles
Lawrence S
LS
Zea-Ponce
Yolanda
Y
Mawlawi
Osama
O
Martinez
Diana
D
Mitropoulou
Vivian
V
O'Flynn
Karen
K
Koenigsberg
Harold W
HW
Van Heertum
Ronald
R
Cooper
Thomas
T
Laruelle
Marc
M
Siever
Larry J
LJ
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
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