Marty O’Rourke, who discipled me when I was young in the Christian faith, would sometimes tell others that when he first met me, I was smoking a joint. Technically, I had just taken a toke and was passing the joint to another person. Yes, I did sometimes smoke marijuana in the 1970s and I did inhale. But I never went on to try harder drugs. There was no “gateway effect” with my marijuana use.

There has been a back-and-forth debate for years about whether or not marijuana is a “gateway” drug. Typically three truths support the idea:

• Marijuana users are more likely than nonusers to progress to hard-drug use.
• Almost all the individuals who have used both marijuana and hard drugs first used marijuana.
• A higher frequency of marijuana use raises the likelihood of using hard drugs at a later time.

But like me, the overwhelming majority of marijuana users do not progress to other drugs.  The 2012 National Survey on Drug Use and Health found marijuana was the most commonly used illicit drug, with 18.9 million users in the month prior to the survey. This constituted 79 percent of all the reported illicit drug use. About two thirds (62.8%) of illicit drug users had used only marijuana in the past month.

Sociologists say marijuana is typically used within a specific social context. So the progression to more dangerous drugs happens as a result of the person associating with a subculture that condones drug experimentation. The social group, not marijuana, is the “gateway.”

Similarly, Andrew Morral suggested there was a common factor explanation for the gateway effect with marijuana. The individual’s opportunities and inclination determine the risk of future hard drug use, not prior marijuana use. He commented that his research did not disprove the gateway theory. But it showed another plausible explanation for the association of marijuana use and hard drug use.

The Marijuana Policy Project listed several articles (i.e., Is Marijuana a “Gateway Drug”?) that challenged the marijuana gateway theory. However, the articles tended to conclude there was a common factor explanation or a mediating factor, like stress or genetics, to the gateway effect with marijuana. They debunked the notion of marijuana use as a causative factor leading to harder drug use, but they do not effectively challenge the above three facts supporting the marijuana gateway theory.

Counseling people with drug and alcohol problems has shown me that they often experimented with marijuana before trying harder drugs. The three statements above have been true time and time again. Marijuana use may not be a causative gateway to future experimentation with more dangerous drugs, but it was often a stepping stone taken before an individual tried the cocaine, heroin, or prescription drug high. And a recent study by researchers at Yale concluded that previous alcohol, cigarette and marijuana use were each associated with the current abuse of prescription opioids. “Previous marijuana use was 2.5 times more likely than no previous marijuana to be associated with subsequent abuse of prescription opioids.”

The executive director of the Connecticut chapter of NORML, Erik Williams, said the Yale study failed to show a strong link between marijuana and the use of harder drugs. “This is just another propaganda study that tries to turn a casual link into a causal relationship.” The Yale’s study lead author agreed there wasn’t proof of a concrete connection between opioid abuse and prior marijuana use. But, she said, “It’s a red flag.” It suggests there is a potential association there.

Marijuana does not seem to be a “gateway” that leads to experimentation with more dangerous drugs. But it often is a stepping stone taken on the path to harder drugs in a person’s addictive career.