Every year, the National Survey on Drug Use and Health asks Americans about their use of cannabis and other drugs. The results of the 2015 survey, released recently, show that 8.3 percent of Americans aged 12 and up said they had used cannabis at least once in the past month. Meanwhile, 13.5 percent said they had used cannabis at least once in the past year. These rates are essentially unchanged from 2014 and equate to approximately $6.7 billion in legal cannabis sales.
The survey's data are also broken down by state and show that cannabis use varies considerably across regions of the country. Not surprisingly, more people on the West Coast, Colorado and the Northeast report using more cannabis than people in the Midwest and Deep South.
And the regional differences are not small. In places such as Colorado and Washington, D.C. nearly 25 percent of people reported using cannabis at least once in the past year. That's almost twice the national average and nearly three times more cannabis use than in states such as Utah, Alabama and Mississippi.
The pattern on the national cannabis use map may look familiar. Consider, for example, the map showing the adult obesity rate by state in 2010. Obesity is highest in the Midwest and Deep South and lowest on the West Coast, in the Northeast and Colorado—opposite to the pattern of cannabis use. Contrary to the tired stoner stereotype of users "getting the munchies," the maps show that obesity has what scientists call an inverse correlation with cannabis use.
Is cannabis effective as a weight-loss aid? Scientific studies do consistently show that cannabis users have a lower body mass index than non-users. But the causes of this association between cannabis use and healthy weight in adults are not clear, thanks mostly to the federal government's ban on cannabis-related research. What is clear is that cannabis does not "make" users fat or lazy.
The national pattern of cannabis use also shows an eerie resemblance to the pattern that appeared in nightmares across the nation on Nov. 9 last year. Generally speaking, Hillary voters are using much more cannabis than Drumpf voters. Conservatives will no doubt say that that frequent cannabis use may be the cause of liberals' "poor judgment," but the patterns of mental health are far more likely to follow the patterns of physical health than vice versa.