Altered dopaminergic function and negative symptoms in drug-free patients with schizophrenia. [123I]-iodobenzamide SPECT study.
BACKGROUND
Previous in vivo studies of schizophrenia with dopamine D2 receptor radioligands have yielded contradictory results. No prior study has used multiple scans to examine within-subject clinical change.


METHODS
Twenty-one patients were studied with [123I]-iodobenzamide single photon emission computed tomography about two weeks after neuroleptic withdrawal. Thirteen of the 21 completed a second scan about four weeks after neuroleptic withdrawal. Sixteen controls were scanned for comparison.


RESULTS
There was no significant difference between groups in [123I]-iodobenzamide uptake at either scanning session. No significant correlations with demographic variables (age, illness duration, drug-free period), or clinical ratings (positive and negative symptoms, movement disorder) were observed at either scanning session. There was a significant correlation between change in [123I]-iodobenzamide uptake and change in negative symptom ratings for the subjects who underwent two scans (r = 0.72, P < 0.05).


CONCLUSIONS
Worsening of negative symptoms may be associated with increased availability of striatal D2 receptors, perhaps because of decreased concentrations of endogenous dopamine.
Knable
M B
MB
Clinical Disorder Branch, National Institute of Mental Health, Washington, DC 20032, USA.
Egan
M F
MF
Heinz
A
A
Gorey
J
J
Lee
K S
KS
Coppola
R
R
Weinberger
D R
DR
D000328:Adult; D014150:Antipsychotic Agents / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000378:metabolism*; D013375:Substance Withdrawal Syndrome / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
D014150:Antipsychotic Agents; D004298:Dopamine