LOWER LEFT TEMPORAL-LOBE MRI VOLUMES IN PATIENTS WITH FIRST-EPISODE SCHIZOPHRENIA COMPARED WITH PSYCHOTIC-PATIENTS WITH FIRST-EPISODE AFFECTIVE-DISORDER AND NORMAL SUBJECTS

Objective: Magnetic resonance imaging (MRI) studies of schizophrenic p atients have revealed structural brain abnormalities, with low volumes of gray matter in the left posterior superior temporal gyrus and in m edial temporal robe structures. However, the specificity to schizophre nia and the roles of chronic morbidity and neuroleptic treatment in th ese abnormalities remain unclear. Method: Magnetic resonance (1.5-T) s cans were obtained from 33 patients with first-episode psychosis and 1 8 age-matched normal comparison subjects, all right-handed. Sixteen of the patients were diagnosed with affective disorder and 17 with schiz ophrenia. Results: Quantitative volumetric analysis showed that the pa tients with first-episode schizophrenia had significantly smaller gray matter volume in the left posterior superior temporal gyrus than did the patients with first-episode affective psychosis or the comparison subjects, with a significant left-less-than-right asymmetry. The schiz ophrenic patients also showed a smaller gray matter volume of the left posterior amygdala-hippocampal complex than the comparison subjects. Both the patients with schizophrenia and those with affective psychosi s had significant left-less-than-right asymmetry of the posterior amyg dala-hippocampal complex. Conclusions: These findings suggest that tem poral lobe abnormalities are present at the first hospitalization for schizophrenia and that low volume of the left posterior superior tempo ral gyrus gray matter is specific to schizophrenia compared with affec tive disorder.