Naltrexone, a drug used to treat alcoholics, may be most effective in those alcoholics where the disease runs in the family, according to research from the National Institute of Alcoholism and Alcohol Abuse.

Although prior studies showed that naltrexone -- one of four FDA-approved drugs used to treat alcoholism -- had a modest effect (but not overwhelming), this new research concluded that it was very effective. That is, only if the alcoholism being treated was passed down through genes.

The results from the study that concluded with this suggestion are quite fascinating, as naltrexone failed to produce significant benefits in overall trials, but succeeded nicely in subgroups that were studied, which led researchers to probe further into possible root causes of alcoholism.