“They compared the results of the Oreo and rice cake test with results from rats that were given an injection of cocaine or morphine, known addictive substances, on one side of the maze and a shot of saline on the other. Professor Schroeder is licensed by the U.S. Drug Enforcement Administration to purchase and use controlled substances for research.

The research showed the rats conditioned with Oreos spent as much time on the “drug” side of the maze as the rats conditioned with cocaine or morphine.”

– http://www.conncoll.edu/news/news-archive/2013/student-faculty-research-shows-oreos-are-just-as-addictive-as-drugs-in-lab-rats-.htm#.Ul3oLRZ0-5f