University of Adelaide news release In a major breakthrough, an international team of scientists from the University of Adelaide and University of Colorado Boulder has proven that addiction to morphine and heroin can be blocked, while at the same time increasing pain relief. The team has discovered the key mechanism in the body鈥檚 immune system that amplifies addiction to opioid drugs. Laboratory studies involving rats have shown that the drug (+)-naloxone will selectively block the immune-addiction response.