INCREASED plasma activity of the enzymes creatine kinase (CPK) or aldolase, or both, has been reported to occur in a large percentage of acutely psychotic patients of all diagnostic types.^1-7The increases in CPK activity are generally five to ten times the upper limits of normal, which, in our laboratory, are 50 international units (IU) per liter for hospitalized patients, 80 IU/ liter for fully active individuals^3,5; the in creased aldolase activity is usually two to three times the upper limits of normal. The increases usually occur in the first and second weeks of a psychotic episode, but may occur earlier or later. Details of the correlations of enzyme activity with clinical course have been presented elsewhere.^3-6

CPK and aldolase occur in multiple molecular forms called isoenzymes, which are separable by appropriate physicochemical methods.⁸ The type of CPK and aldolase present in