We measured CSF and plasma contents of beta-endorphin (beta-EP), beta-lipotropin (beta-LPH), and ACTH in 24 patients with Parkinson's disease; 14 had not been treated. CSF beta-EP concentrations in untreated patients were lower than in 15 controls (p less than 0.005), but values did not differ significantly in treated and untreated patients. In untreated and treated patients, ACTH and beta-LPH CSF, and beta-EP, beta-LPH, and ACTH plasma concentrations were in the same range as controls. The Parkinson's disease-related decrease of CSF beta-EP levels further supports the concept that there is a generalized brain disorder in Parkinson's disease affecting more than dopaminergic neurons in the substantia nigra.