Subcortical MRI volumes in neuroleptic-naive and treated patients with schizophrenia

Objective: This study examined whether subcortical volumes of the basal gan glia and thalamus in schizophrenic patients are related to neuroleptic expo sure and symptom severity. Method: Basal ganglia substructures and thalamic volumes were measured with magnetic resonance imaging in 96 patients with schizophrenia (50 men and 46 women) and 128 healthy comparison subjects (60 men and 68 women). Twenty-one of the patients were neuroleptic-naive; of t he 75 previously treated patients, 48 had received typical neuroleptics onl y, and 27 had received typical and atypical neuroleptics. The relation of v olume measures to treatment status, exposure to neuroleptics, and symptoms was examined. Results: The neuroleptic-naive patients did not differ from t he healthy comparison subjects in subcortical volumes except for lower thal amic volume. In the neuroleptic-naive group, volumes did not correlate with severity of negative symptoms, but higher volumes in both the thalamus and the putamen were associated with more severe positive symptoms. The previo usly treated group showed higher volumes in the putamen and globus pallidus than the healthy comparison subjects and the neuroleptic-naive patients. i n the treated group, a higher dose of a typical neuroleptic was associated with higher caudate, putamen, and thalamus volumes, whereas a higher dose o f an atypical neuroleptic was associated only with higher thalamic volume. Higher subcortical Volumes were mildly associated with greater severity of both negative and positive symptoms. Conclusions: Increased subcortical vol umes in treated schizophrenic patients seem to be medication-induced hypert rophy. This hypertrophy could reflect structural adaptation to receptor blo ckade and may moderate the effects of neuroleptic treatment.