The authors conducted single- and double-blind studies of the responses
of 7 chronic male schizophrenic patients to 10 mg of naloxone. BPRS ratings
were made before and 6 hours after the injection; ACTH blood levels were
determined before and 1 1/2 and 6 hours after injection. Statistically
significant improvement of psychotic behavior occurred after 6 hours. The
greatest improvement occurred in the patient who showed the most pronounced
diurnal variation of ACTH levels, and there was no improvement in the
patient who had no diurnal changes. Prolactin plasma levels following
endorphin injections were apparently dose- dependent and peaked at
approximately 30 minutes. The mean half-life of elimination of exogenous
beta-endorphin was between 12 and 35 minutes. The authors theorize that
positive and negative behavioral responses to naloxone depend--as possibly
do many placebo responses in general--on the relative stress produced by
experimental or therapeutic interventions.Abstract Teaser