It's a drug that's been around for 30 years to fight addictive behaviors such as alcoholism, but researchers at the University of Minnesota have recently found another use for Naltrexone: preventing kleptomania, the recurring urge to steal. In studies of shoplifters, associate professor of psychiatry Jon Grant discovered that those receiving the drug experienced a significantly reduced desire to steal. To understand how it works, Grant says you must first understand how the brain handles pleasure.