Spinal fluid samples from psychotic patients were examined for creatine phosphokinase (CPK). Increased enzyme activity was found in 12 out of 40 patients. Creatine phosphokinase values ranged from 1 to 11 international units (IU)/100 ml; mean, 4 IU ± 3.5 SD.
Patients showing increased CPK values in spinal fluid were those in whom the psychotic state was in the acute phase of evolution. No other clinical correlation could be determined.