THE INVENTIONS DESCRIBED HEREIN AROSE FROM UNEXPECTED DISCOVERIES MADE DURING CLINICAL TRIALS WITH A LONG ACTING FORMULATION OF NALTREXONE. AS SUCH, THE INVENTION INCLUDES A METHOD FOR TREATING AN INDIVIDUAL IN NEED OF NALTREXONE COMPRISING THE STEP OF PARENTERALLY ADMINISTERING A LONG ACTING FORMULATION COMPRISING NALTREXONE AND TO THE USE OF NALTREXONE IN THE MANUFACTURE OF MEDICAMENTS FOR USE IN SUCH METHODS.