Middle ear muscle activity during REM sleep in schizophrenic, schizoaffective and depressed patients

The authors measured the middle ear muscle activity during REM sleep of normal subjects (N = 13) and patients with schizophrenia (N = 11), schizoaffective disorder (N = 8), or major depressive disorder (N = 10). The rates of middle ear muscle activity for 5 schizophrenic patients were higher than the highest rates of the other groups. The patients with major depressive disorder had normal rates, and the rates of those with schizoaffective disorder were below normal. Within the schizophrenic patients, high middle ear muscle activity could not be directly attributed to background sleep disturbances, age, anxiety, depression, or diagnostic subtype.