주요정 신병 에서의 수면뇌 파와 Dexamethasone 억제 검사

Electroencephalographic Sleep Findings and Dexamethasone Suppression Test in Major Psychotic Disorders

The authors tried to evaluate the clinical utility of electroencephalographic^EEG) sleep findings which has been proposed as objective and reliable biological marker in schizophrenia and major depression. EEG sleep characteristics of schizophrenia(N= 12) were compared with those of normal controls(N= 17) and major depression(N= 6). In addition, dexamethasone suppression test (DST) was done on the subjects. We assessed the relation between the findings of these biological markers and clinical variables. The results were as follows ; 1) There appeared increased REM density and diminished first stage 4 proportion in all schizophrenics. REM latencies of chronic schizophrenics were significantly shortened as compared to those of normal controls and subchronic schizophrenics. Cortisol level to DST tended to show nonsuppression, and REM latencies were not altered in the subchronic schizophrenics. With progression of the illness, it appeared that cortisol level became normalized and REM latency became shortened. 2) Major depressives showed significantly diminished stage 4 percentage and increased first REM period in comparison to those of normal controls. The non-suppressors to DST tended to show shortened REM latency. 3) On the bases of the sleep findings, such as the first stage 4，REM latency and stage 4 percentage, it could be suggested that REM sleep of schizophrenics and major depressives was shifted toward sleep onset. In summary, this study shows that there are some abnormal findings of sleep EEG and DST in schizophrenia. The combination of sleep latency and DST findings could be used as differentiating points for the clinical variables, such as course of illness, in schizophrenia. So the authors suggest that sleep EEG and DST findings might be useful as reliable biological markers in psychiatric fields.