REM phase deprivation and schizophrenia II.

Nine schizophrenic patients with active symptomatology were compared with seven patient controls in their response to two nights of rapid eye movement (REM) sleep deprivation. The control subjects demonstrate "normal" increases in total REM and percentage REM time increase on recovery nights compared to base line nights. The schizophrenic subjects differ substantially from the control subjects in both these measurements and show no perceptible change from base line nights on recovery nights. The effects of medication, anxiety, sleep loss, ceiling effects, and intensity change were not considered adequate to account for the above results. However, many questions, such as the specificity of this rebound failure to the schizophrenic patients and the possibility of a sleep disturbance factor operating independently of psychiatric diagnosis, remain to be answered.