Assessment of naltrexone in the treatment of schizophrenia.

Naltrexone, a long acting opiate antagonist, and placebo were administered to eight schizophrenics in doses of 200 mg per day for 1 week in a double-blind, crossover design. No improvement was noted, and no side effects resembling the opiate withdrawal syndrome with naltrexone were found. Naltrexone does not appear to alter schizophrenic symptomatology.