Lower striatal dopamine transporter binding in neuroleptic-naive schizophrenic patients is not related to antipsychotic treatment but it suggests an illness trait.

Abstract:

INTRODUCTION: Drug induced parkinsonism (DIP) is directly related to dopamine D2 receptor blockade. However, there are many references describing parkinsonian signs (PS) in naive-patients. In our previous study, we observed lower DAT binding in a group of first-episode schizophrenic patients after short-term treatment with risperidone, compared with age-matched healthy controls. AIM: To clarify if DAT decrease could be an illness trait, excluding the effect of antipsychotics on DAT availability, and to determine whether DAT availability before treatment with antipsychotics may predict subsequent development of PS. MATERIALS AND METHODS: A new series of 20 neuroleptic-naive schizophrenic patients and 15 healthy subjects was recruited. SPECT with [(123)I] FP-CIT (DaTSCAN(R)) was performed before starting antipsychotics and after 4 weeks of treatment. PS and psychopathological status were assessed by the Simpson-Angus (SAS), CGI and PANSS scales. Quantitative analyses of SPECTs were performed using ROIs placed in the caudate, putamen and occipital cortex. RESULTS: Schizophrenic patients showed lower DAT binding compared with the healthy subjects at baseline (p