A longitudinal study of cerebrospinal fluid beta-endorphin-like immunoreactivity in delirium: changes at the acute stage and at one-year follow-up.

Cerebrospinal fluid beta-endorphin-like immunoreactivity (CSF BLI) was determined on 3 occasions for elderly delirious patients and the BLI levels were compared with age-equivalent controls. Delirious patients showed a significant reduction in the BLI values in the first sample and a declining trend was seen in the follow-up. The results suggest a role for beta-endorphinergic dysfunction in the genesis of some symptoms of delirium, and this dysfunction may be a common phenomenon in various forms of delirium and dementia.