PROVIDENCE, R.I. [Brown University] -- Combining the drug topiramate with psychological counseling curbed marijuana use among young smokers significantly more than did counseling alone, according to newly published results of a small randomized, controlled trial at Brown University. The results come with a caveat, however: many study volunteers couldn't tolerate the medicine's side effects.

There is no FDA-approved medication for treating cannabis dependence and misuse. Meanwhile, the benefits of counseling treatment, such as motivational enhancement therapy (MET), aren't enough to help many patients, said Robert Miranda Jr., associate professor (research) of psychiatry and human behavior in the Alpert Medical School.

Miranda and his co-authors conducted the trial as the first test to determine whether topiramate, an epilepsy drug marketed as Topamax, could add to the benefits of MET. Previously, researchers including Miranda have studied topiramate as a potential treatment for alcohol and nicotine dependence and cocaine addiction.

The results show...