Elevated levels of N-acetyl-beta-glucosaminidase in affective disorders and chemical dependence.

Levels of N-acetyl-beta-glucosaminidase (NAG) were examined in 575 patients with various psychiatric diagnoses and 38 non-ill controls. Ten percent of affectively disordered patients and 19% of chemically dependent patients had abnormal NAG levels, whereas none of the 38 controls did (P less than 0.05 and P less than 0.003 respectively). Other psychiatric diagnostic groups were not associated with abnormal levels of this enzyme.