Cerebrospinal fluid concentrations of beta-endorphin in chronic low back pain patients. Influence of depression and treatment.

Cerebrospinal fluid (CSF) beta-endorphin concentrations were determined before and after treatment in 28 patients suffering chronic neuralgic low back pain/sciatica. Nine patients carried the additional diagnosis of major depressive disorder. Pain treatment was multimodal and resulted in variable pain reduction. CSF beta-endorphin concentrations spanned a wide range with no association to age, gender, pain ratings, depressive symptomatology, and drug intake. CSF beta-endorphin concentrations were not influenced by the presence of major depressive disorder and did not change with successful treatment of pain and resolution of depression.