CSF beta-endorphin-like immunoreactivity in delirium

Cerebrospinal fluid beta-endorphin-like immunoreactivity (CSF BLI) was determined for 69 patients who met DSM-III criteria for delirium and for 8 controls. The CSF BLI was significantly lower in the delirious patient group than in the controls (12.5 +/- 3.0 pg/ml versus 15.0 +/- 3.4 pg/ml, p less than 0.05). CSF BLI had no correlation with age or neuroleptic drug dosage, but did have a significant positive correlation with cognitive functioning as evaluated by the Mini-Mental State. Our findings suggest a role for beta-endorphinergic dysfunction in the development of delirium.