Is Cannabis Addictive?
A researcher from Washington University in St. Louis says that a highly publicized study is wrong about its claim that the number of people with marijuana addictions has risen. Therefore is marijuana addictive?
The original study, which was published in the journal JAMA Psychiatry in December 2015, was based on a series of face-to-face interviews about people’s marijuana use patterns.
It concluded that “the prevalence of marijuana use has more than doubled between 2001-2002 and 2012-2013, and there was a large increase in marijuana use disorders during that time.”
Marijuana use disorders are defined as any condition in which a person becomes dependent on cannabis. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classifies marijuana use disorders as a set of conditions serious enough to require treatment.
In the wake of the December 2015 study, news sources throughout the country published articles detailing the study’s claim that the significant spike in overall marijuana use has led to a subsequent spike in the number of people with marijuana use disorders.
But now, Dr. Richard Grucza has challenged the fundamental premise of that study.
He recently told reporters in St. Louis that the original study was potentially flawed since it relied on a series of face-to-face interviews, which he says are much more unreliable than anonymous interviews.
To test whether or not a different survey methodology would yield different results, Grucza conducted his set of surveys using anonymous computerized questionnaires.
The data his study generated were markedly different from the findings of the December 2015 study.
To begin with, he said that the number of adults using marijuana over the last decade or so has increased by 20 percent. And while he said that is a significant number, it is much lower than the original study’s claim that adult marijuana use has doubled.
He also found differences in the prevalence of marijuana use disorders.
“About 10 or 15 percent of the people who have used in the last year are using some problematic level,” he explained.
“What we are finding is that ratio has gone down. So, the percentage of users that have problems with marijuana has decreased over the past ten years.”