The case for and against legalizing marijuana (Part I: health)

The issue of whether to legalize marijuana (recreationally, not medically, to be clear) is a depressingly politicized one, which I will try to get to the bottom of here (though this is of course a task far too daunting for one blog post, so I won't cover everything out of necessity). At least one politician has been caught claiming that marijuana is "infinitely worse" than tobacco. (1) But if you read the New York Times (which 1.87 million people do every day) (3) you may hear that in criminalizing marijuana the federal government has "inflict[ed] great harm on society just to prohibit a substance far less dangerous than alcohol." (4) The implication to all these statements is that legal drugs should be those that aren't that harmful compared to their illegal counterparts. So are there any studies comparing the safety of marijuana with that of legal drugs?

The answer appears to be yes, but not as many as one would expect, given that this issue is so important with respect to drug laws and so widely discussed. Or at least, I would expect. One of the most highly publicized studies in this area was published earlier this year, to considerable media attention. (5) Its conclusions were that alcohol and tobacco are considerably more harmful than marijuana. In fact, at one point, the authors say that alcohol is the highest-risk drug, while pot is the lowest-risk one. They also point out that their results are in line with those of Nutt et al., (6) whose (also highly publicized) results found that marijuana was overall the 8th most dangerous drug, with alcohol and tobacco in 1st and 6th places, respectively. 

So what does this mean? If it is true that, as discussed above, marijuana is safer than tobacco or alcohol, does that mean we have to legalize it? Not necessarily, because economic issues could arise that would make doing so unfeasible, and this will be discussed in the next post. Nevertheless, it suggests that our current drug laws don't really make sense, as Nutt et al. noted ("the findings correlate poorly with present UK drug classification, which is not based simply on considerations of harm.") (6) So there are two ways to fix this: we could make alcohol illegal, or we could make the illegal drugs that are less dangerous than it legal (or both). The former, of course, has already been tried, and it failed--or at least that's what everyone thinks. Even the Times started out its pro-legalization op-ed by saying that "It took 13 years for the United States to come to its senses and end Prohibition, 13 years in which people kept drinking, otherwise law-abiding citizens became criminals and crime syndicates arose and flourished." (4) Since this post is about health, I will focus on three words in the previous quote: "people kept drinking". The problem with this claim is that it's not true: alcohol consumption plummeted during prohibition, as did death rates from cirrhosis and hospital admissions for alcoholic psychosis. (7) 

So this means that, presumably, making something illegal makes people use it less, and vice versa. For this reason, the White House argues that "Increased availability and acceptability of marijuana would likely lead to increased consumption of the drug," which, in turn, "leads to higher public health and financial costs for society." (8)

The research suggests that marijuana is not harmless, but that it is nowhere near as harmful as tobacco or alcohol, both of which are, of course, legal. This in-between status makes it hard to decide what to do with it--legalization advocates want to drag it to the (almost) harmless side, but their opponents want to exaggerate its dangers.

I think that marijuana legalization is justifiable from a public health perspective only if we make alcohol and tobacco (which kill 3.3 million (9) and almost 6 million people per year (10)) illegal, in order to be consistent. At the very least, keeping it in the schedule I category is clearly unjustifiable.

Part 2 of this series will be titled "The case for and against legalizing marijuana (Part II: economics)".

Sources

1. http://www.chicagotribune.com/news/opinion/chapman/ct-marijuana-legalization-canada-mexico-perspec-1108-20151106-column.html

2. https://www.whitehouse.gov/ondcp/ondcp-fact-sheets/marijuana-legalization

3. http://www.bloomberg.com/news/articles/2013-04-30/new-york-times-leads-major-newspapers-with-18-circulation-gain

4. http://www.nytimes.com/interactive/2014/07/27/opinion/sunday/high-time-marijuana-legalization.html

5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311234/

6. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(10)61462-6/abstract (full text http://www.sg.unimaas.nl/_old/oudelezingen/dddsd.pdf)

7. http://www.nytimes.com/1989/10/16/opinion/actually-prohibition-was-a-success.html

8. https://www.whitehouse.gov/sites/default/files/ondcp/issues-content/marijuana_and_public_health_one_pager_-_final.pdf

9. http://www.who.int/mediacentre/factsheets/fs349/en/

10. http://www.cdc.gov/tobacco/data_statistics/fact_sheets/fast_facts/