San Francisco has highest level of marijuana smokers

Nationally, report finds lowest use rates in the South.

Take a bow, San Francisco: The Bay Area is home to the highest concentration of marijuana smokers anywhere in the country, according to new data released this week by the Substance Abuse and Mental Health Services Administration.

Every few years, SAMHSA combines data from the annual National Surveys on Drug Use and Health to derive estimates of monthly marijuana use among Americans age 12 and older. The latest cut of that data, encompassing the years 2012 to 2014, include responses from approximately 204,000 people. That huge sample makes it possible to visualize marijuana use rates with a level of detail not possible with traditional surveys.

Over 15 percent of San Francisco residents age 12 and over use marijuana monthly or more often, the highest rate in the country, the survey found. By contrast, the lowest use rates are in the far south of Texas, where fewer than 4 percent use marijuana monthly.

The report finds that nationally, 7.7 percent of people 12 and older — roughly 20.3 million Americans — use marijuana at least once a month. Broadly speaking, marijuana use rates are highest in the Western states and lowest in the South.

“We continue to see relatively wide variation in marijuana use” at the sub-state level, said Art Hughes, a SAMHSA statistician and a lead author on the report, in an interview. Overall marijuana usage rates were up by less than 1 percentage point over the period from 2010 to 2012.

Marijuana use rates have become a hot topic since Colorado established the first legal marijuana market in 2014, with several other states following suit. But since this data mostly covers the period before 2014, SAMHSA’s Hughes says it does not reflect the effects of legalization.

Marijuana use in Colorado is relatively high, but it’s been that way for quite a while.

“There are some states where we see rates on the high end even before legalization,” Hughes said.

Different states have had radically different marijuana policies in place for years now, evident in the sometimes stark differences in use rates on either side of a state border.

The high use rates in Colorado — where marijuana has been decriminalized for some time and medical marijuana has been available for years — can be compared to the rock-bottom usage across the state line in far stricter Kansas. Of course, the causality could run both ways — states where people are naturally inclined to use more marijuana may end up enacting looser marijuana laws.

Despite that, some researchers are starting to question the link between attitudes about marijuana’s harmfulness and rates of use of the drug. For instance, federal surveys have shown that fewer and fewer high school students say there’s a great risk of harm in using marijuana. And yet, marijuana use rates among that group have also fallen.