SINCE the nature and etiology of acute psychosis are still obscure, the establishment of any abnormal biological parameters for acutely psychotic patients, irrespective of whether such parameters relate to cause or effect of the psychosis, would be of considerable interest. Recently, severe sleep disturbances affecting both rapid-eye-movement (REM) sleep and nonrapid-eye-movement (NREM) sleep were reported in patients having psychotic depressions and acute schizophrenic episodes.1 Secondly, increased activity of creatine-phosphokinase (CPK) (ATP-creatine phosphotransferase) in serum was found in patients having recent onsets of psychosis.2-4 Both types of abnormalities seem to be present mainly at the onset of the acute psychotic episode and generally last from several days to two weeks, with occasional exceptions. It is of interest that both types of biological abnormalities are present in acutely psychotic patients of a variety of diagnostic types, including patients with manic-depressive psychosis, psychotic depressions, and