Long-term stability of measuring D2 receptors in schizophrenia patients treated with antipsychotics

Abstract: Background: While antipsychotic-free schizophrenia patients showed a high degree of within-subject variability in dopamine D2 receptor density over 6–24 months, no study has examined the long-term stability of D2 receptor measures in medicated patients. Methods: Four schizophrenia patients receiving a stable dose of risperidone underwent [11C]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 D2 binding potential and D2 occupancy were good. Conclusions: The finding supports the validity of quantification of D2 receptor binding in longitudinal PET studies of medicated patients with schizophrenia. [Copyright &y& Elsevier]