Because the opiate antagonists appear to be effective in the treatment of pathological gambling (PG), it is reasonable to ask whether acamprosate (calcium acetylhomotaurine; Campral), also FDA approved for the treatment of alcoholism, can be used effectively to treat PG. Acamprosate is not an opioid antagonist; rather, it is assumed that its therapeutic effects are due to actions on GABA receptors. Acamprosate is structurally related to 1-glutamic, which is an excitatory neurotransmitter. It has been proposed that acamprosate decreases the effects of the naturally-occuring excitatory neurotransmitter glutamate in the body. Because chronic alcohol consumption disrupts this system, and the changes last many months after alcohol ingestion is stopped, it is possible that acamprosate restores the glutamate system towards normal. Regardless, acamprosate decreases the pleasant "high" associated with alcohol consumption, and thus decreases the frequency of relapse during abstinence. We hypothesize that acamprosate will have similar actions in persons with PG.