Anti-drug advocates who have admonished for years that marijuana is a "gateway drug" may be on to something, according to a study by Yale University School of Medicine researchers.

The Yale study, which appears online in the Journal of Adolescent Health, showed that alcohol, cigarettes and marijuana were associated with an increased likelihood of prescription drug abuse in men 18 to 25. In women of that age, only marijuana use was linked with a higher likelihood of prescription drug abuse.

For years, researchers have looked at a connection between marijuana and hard drugs, such as cocaine and heroin, said Lynn Fiellin, the study's lead author and an associate professor of medicine at the Yale University School of Medicine. But given the large number of people who abuse prescription drugs -- particularly opioids (or painkillers) such as OxyContin and Percocet -- Fiellin said it seemed worthwhile to examine whether there was a link between marijuana and use of these drugs.

The study found that, among both men and women, those who had used marijuana were 2.5 times more likely than those their age who abstained to later dabble in prescription drugs. Also, young men who drank alcohol or smoked cigarettes were 25 percent more likely to abuse prescription opioids. However, the study didn't show an association between alcohol or cigarette use in young women and later use of prescription drugs.

Fiellin conceded that more research is needed to prove a concrete connection between opioid abuse and marijuana, alcohol and cigarettes. However, Fiellin said, this study is a start. "It's a red flag," she said. "It sort of highlights that there's a potential association that's important here."

Source: Hartford Courant
http://www.courant.com/news/breaking/hc-yale-marijuana-gateway-0822-20120822,0,726579.story