The drug war tweety birds are out with an exciting new study purporting to show that marijuana is a gateway drug to more addictive substances — like demon rum.
That’s right, the study, which was published in Jama Psychiatry, found that pot use could lead to — wait for it — “alcohol abuse.”
According to Reuters, the study surveyed “a nationally representative sample” of 34,653 U.S. adults three years apart — first in 2001-02 and again in 2004-05. The sample was almost evenly split among men and women, with an average age of 45.
In the first survey, 1,279 respondents reported using marijuana. Three years later, “that was linked to a nearly three times higher rate of abusing alcohol compared to people who didn’t use cannabis in the first survey.”
But wait. There’s more. The risk of pot smokers abusing other drugs or being dependent on tobacco was twice as high as that for people who didn’t use pot. And the risk of having a “cannabis abuse disorder” (whatever that means) by the second survey was nine times higher.
The study’s senior author, Dr. Mark Olfson of Columbia University Medical Center and the study team took care to point out that these associations don’t prove cannabis causes other substance abuse problems (that correlation isn’t causality in other words).
Then Olfson started talking like it did.
“Patients who may be considering using cannabis should know that by using cannabis they are approximately doubling their risk of developing a drug use disorder over the next few years,” he told Reuters in an email.
And just in case there might be any doubt that the study had a political agenda, Dr. Olfson thoughtfully spelled it out.
“Policymakers who may have to vote on legalization of marijuana should consider potential adverse effects of marijuana use on the risks of developing other drug and alcohol abuse problems,” he said. “In states with marijuana laws that permit recreation marijuana use, regulators and public health officials should develop means of monitoring and communicating this risk.”
Alas, the results of Dr. Olfson’s study should, how should we say this tactfully, be viewed with caution.
That’s because there is an inconvenient fly in Dr. Olfson’s cannabis ointment. It turns out the study’s sample ludicrously under-represents the number of Americans who use marijuana.
The study’s 1,279 pot smokers constituted just 3.7 percent of its 34,653 respondents.
In 2002 (the year Dr. Olfson completed his first survey) and every year since, the United Nations Office of Drugs and Crime, which tracks the prevalence of drug use in UN member states, put the proportion of Americans who had smoked pot over the past year at 11 to 12 percent of the population.
In other words, when it comes to cannabis use, Dr. Olfson’s sample is not “nationally representative” — which raises questions about how “nationally representative” the cohort of respondents is in other respects. Like does it under-represent alcohol abusers? And in what ways might a skewed respondent cohort skew the study’s findings and conclusions?
Olfson repeatedly throws around terms like “drug use disorder,” “substance use disorder,” “alcohol abuse,” and “cannabis abuse disorder” without bothering to define them. Given that drug warriors have habitually (so to speak) conflated the terms “use” and “abuse” when speaking of marijuana, it’s essential to know if Dr. Olfson is using language with scientific precision or talking prohibitionist trash.
One last point. It’s really hard to take seriously someone who’s trying to portray illegal marijuana as a gateway drug to legal alcohol and legal tobacco. Come on, man! How many teenagers smoked pot and then moved on to beer and cigarettes? OK, I suppose it happened to someone — it’s a big country — but in most people’s experience that doesn’t pass the smirk test. What next, doc? If I start smoking pot, does that mean in three years I’ll be drinking coffee?