Long-term stability of measuring D(2) receptors in schizophrenia patients treated with antipsychotics.
BACKGROUND
While antipsychotic-free schizophrenia patients showed a high degree of within-subject variability in dopamine D(2) receptor density over 6-24 months, no study has examined the long-term stability of D(2) receptor measures in medicated patients.


METHODS
Four schizophrenia patients receiving a stable dose of risperidone underwent [(11)C]raclopride positron emission tomography scans on two occasions 5-14 months apart.


RESULTS
Plasma risperidone levels were found to be consistent between scans, and consistencies of nondisplaceable D(2) binding potential and D(2) occupancy were good.


CONCLUSIONS
The finding supports the validity of quantification of D(2) receptor binding in longitudinal PET studies of medicated patients with schizophrenia.
Uchida
Hiroyuki
H
PET Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, Canada M5T 1R8.
Graff-Guerrero
Ariel
A
Mulsant
Benoit H
BH
Pollock
Bruce G
BG
Mamo
David C
DC
D000368:Aged; D014150:Antipsychotic Agents / Q000097:blood / Q000627:therapeutic use*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000097:blood* / Q000378:metabolism; D018967:Risperidone / Q000097:blood* / Q000627:therapeutic use; D012559:Schizophrenia / Q000097:blood* / Q000000981:diagnostic imaging / Q000188:drug therapy*
D014150:Antipsychotic Agents; D017448:Receptors, Dopamine D2; D020891:Raclopride; D018967:Risperidone