Pubdate: Sun, 22 May 2016
Source: Commercial Appeal (Memphis, TN)
Copyright: 2016 The Commercial Appeal
Author: Beau Kilmer, Los Angeles Times
Note: Beau Kilmer is co-director the Rand Drug Policy Research Center 
and co-author of the recently revised book "Marijuana Legalization."


In six months, California will join Maine, Nevada and probably a few 
other states in deciding whether to legalize large-scale commercial 
production of marijuana. Residents will be inundated with wild claims 
about the promises and pitfalls of these initiatives.

You will hear debates about government revenue, criminal justice 
benefits, the environment and the effect of legalization on Mexican 
drug-trafficking cartels. Public health conversations may prove 
especially contentious. Some will claim that legalization will 
constitute a net gain for health. Others will say the exact opposite.

Although you shouldn't believe either extreme, one fairly safe bet is 
that if we legalize and allow profit-maximizing firms to produce, 
sell, and advertise recreational marijuana, use will increase.

The data from Colorado and Washington, where voters legalized 
recreational marijuana in 2012, are still preliminary. We do know, 
however, that the number of Coloradans who reported using marijuana 
in the past month increased from about 10.5 percent in 2011-12 to 
nearly 15 percent in 2013-14. In Washington, reported use rose from 
just above 10 percent to almost 13 percent.

Given that both states' pre-existing medical systems already provided 
quasi-legal availability, it is hard to imagine that commercial 
legalization did not account for at least some of these increases. 
(That said, other factors could influence marijuana use and it will 
be some time before researchers have enough data to conduct rigorous 
analyses. Some of the increase could also come from respondents being 
more honest now that marijuana is legal in their states).

But is a rise in marijuana consumption bad from a public health 
standpoint? Not necessarily.

Much will depend on the types of users who account for the increase - 
adults or children? Heavy users or light users? No one wants kids to 
get stoned at school or to become regular users while their brains 
are still developing. No one wants adults to be impaired at work or 
behind the wheel.

Some heavy users, moreover, struggle to control their consumption, 
which can create challenges for them and their families. But there 
are real benefits associated with marijuana use, such as medical 
relief or simply pleasure.

Exactly how people consume marijuana will also help determine public 
health consequences. In addition to vaporizing marijuana plant 
material (which reduces inhalation of carcinogens and other 
substances), people can and do eat, drink, vape hash-oil, and "dab" 
waxes that are high in the intoxicating chemical THC. The negative 
effects of overconsuming edibles are well-documented, but much less 
is known about the pros and cons of these other forms.

Perhaps the most important consideration is how increased marijuana 
consumption may influence the use of other substances.

Although the social costs of heavy alcohol use are much larger than 
the social costs attributable to heavy marijuana use, we do not know 
if legalization will lead to more or less drinking. The research on 
the relationship between alcohol and marijuana use is split down the middle.

This connection is especially important in terms of traffic safety. 
The bulk of the research suggests that driving drunk is more 
dangerous than driving stoned, and driving stoned is worse than 
driving sober. Research also suggests that driving under the 
influence of both alcohol and marijuana is worse than either by itself.

It would be a real blow to public health if an increase in marijuana 
use led to increased tobacco use. Even though the bulk of the 
research suggests this is a possibility, one cannot assume the 
relationship would remain the same under a different legal regime. 
Besides, most of the relevant studies were conducted before 
e-cigarettes and marijuana vape pens became popular, so researchers 
and voters alike have to be careful about making projections.

There is also a new and much smaller body of research suggesting that 
increasing the availability of marijuana reduces problems with opioid 
painkillers. Some of these studies, however, are working papers that 
have not yet been subject to rigorous peer review.

When you vote on whether to legalize marijuana, public health 
consequences may not be at the top of your list. If they are, I'm 
here to tell you the experts have more questions than answers. That 
won't change before November.
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MAP posted-by: Jay Bergstrom