Are a lot more Americans smoking pot or are just a lot more now comfortable admitting they are?

The question in the title of this post is my reaction to this CNN report on new marijuana use research released yesterday.   Here are the basics: 

A heck of a lot more Americans were toking up in 2012-13 than 10 years before — and not for medical reasons, either — according to a new study.  The percentage of American adults who had used marijuana within the last year was 9.5%, the study found.  That compared to 4.1% in 2001-02.

The study — published this week in Jama Psychiatry, a monthly journal published by the American Medical Association — was sponsored by the National Institute on Alcohol Abuse and Alcoholism.  It was based on in-person interviews with more than 36,000 Americans over the age of 18.

With the increase in use has come an increase in the total number of what the study called “marijuana use disorders.”  But the authors of the study put that down to the increase in use:  The percentage of pot smokers with such disorders actually dropped, with about one in three showing signs of dependence or abuse.  As the authors of the study put it, “The prevalence of marijuana use disorder among marijuana users decreased significantly from 2001-2013,” from 35.6 percent of users to 30.6.

The attitudes toward the use of marijuana are shifting in the United States, as are the laws governing its use.  Twenty-three states now allow the use of marijuana for medical reasons, the study notes, and four of those states also allow recreational use of the drug. “Given changing laws and attitudes toward marijuana, a balanced presentation of the likelihood of adverse consequences of marijuana use to policy makers, professionals and the public is needed,” the study said.

I have been struggling this morning to access the full study/article reference in this press report, but I continue to wonder how much identified changes in self-reported marijuana use in recent years reflects changes in self-reporting rates as much as changes in marijuana use rates.  I hope this new study (and any other similar studies about changes in self-reported marijuana use over long periods of time) take this possibility into account. 

I sense that all activities that carry some measure of social stigma (even legal activities like watching pornography or drinking heavily or gambling) are done (a lot?) more than most people will readily admit, and I think the tendency to under-report stigmatized behavior is especially true when an activity involves serious federal and state criminal activity in addition to being shunned by “respectable” people.  Back in 2001-02, the negative stigma (and criminal concerns) surrounding marijuana use was, I think, quite high and claims about valid medical use of marijuana were rarely embraced (especially as compared social views by 2012-13).  For that reason, I wonder if the number of self-reported marijuana users a decade ago was much lower than in more recent years for reasons that are not only about changing rates of actual marijuana use.