Marijuana News August 24, 2012 Yale study: Alcohol Gateway Drug Effect Much Larger Than Marijuana’s Lakota A Yale study published Tuesday in the Journal of Adolescent Health found that the alcohol gateway drug effect is much larger than marijuana’s. People who used alcohol or tobacco in their youth are almost twice as likely to abuse prescription opiate drugs than those who only used marijuana. Categories: Cannabis Facts, Marijuana News Tags: alcohol, gateway drug, gateway effect, Journal of Adolescent Health, study, The Raw Story. By: Lakota. Permalink: .