SHORTENING OF THE HIPPOCAMPAL-FORMATION IN FIRST-EPISODE SCHIZOPHRENIC-PATIENTS

Shortening of hippocampal formation (HF) in chronic schizophrenic pati ents have been demonstrated in our previous study. The purpose of the present study is to test if shortening of the HF occurs in schizophren ic patients suffering their initial psychotic episode. We performed co ntiguous, 1 mm thick, magnetic resonance imaging scans in 20 first-epi sode schizophrenic patients, 21 chronic schizophrenic patients, and 25 healthy subjects. Both groups of schizophrenic patients demonstrated significant shortening of the HF compared with normal controls (first- episode schizophrenia, 5.3%; chronic schizophrenia, 8.0%). However, th e HF length was not significantly different between the first-episode and chronic schizophrenic patients. No significant correlation was see n between the HF length and the duration of illness in chronic schizop hrenic patients. These results suggest that the HF shortening observed in schizophrenic patients may be genetic and/or developmental in orig in.