Association of levels of N-acetyl-beta-glucosaminidase with specific psychiatric symptoms in bipolar patients

The levels of N-acetyl-beta-glucosaminidase (NAG) in urine from 35 patients with bipolar affective disorder were compared with scores for the 90 items (symptoms) of the Symptom Checklist (SCL-90). There were significant negative correlations between NAG levels and 23 of the SCL-90 variables (symptoms). These symptoms could be grouped into the following categories: anxiety, unusual or psychotic thinking, suicidal thinking, dysphoria, irritability, nausea, headaches, memory problems, and loss of interest. Serotonin abnormalities may play a role in the production of many of these symptoms. The hypothesis that NAG could be a marker for a serotonin activity is discussed.