The Correlation Between Marijuana and Violence

“There were opium dens where one could buy oblivion, dens of horror where the memory of old sins could be destroyed by the madness of sins that were new.”

-Oscar Wilde in his novel, ‘The Picture of Dorian Gray‘ (1891).


Throughout the 19th century, opium was one of the most widely used drugs, both medicinally and recreationally.

Pharmacies of the time offered opium and other narcotic drugs, usually mixed with alcohol, herbs, and other ingredients (in some cases even arsenic). The most popular preparation was laudanum, an alcoholic herbal mixture containing 10% opium. Called the ‘aspirin of the nineteenth century,’ laudanum was a popular painkiller and relaxant, recommended for all sorts of ailments including coughs, rheumatism, ‘women’s troubles’ and also, perhaps most disturbingly, as a soporific for babies and young children.

On the recreational side, establishments known as opium dens popped up across Europe and the U.S., catering to rich and poor alike (depending on which establishment you went to, that is).

Literature of the 19th century is fraught with horrific depictions of ghastly opium smokers strewn about the floors of the dens, too inebriated to remain upright. While in the latter part of the century opium dens would become synonymous with criminal activity, there are surprisingly few accounts of violence being a widespread issue in such establishments. This is likely due to the highly sedative effects of the drug.

We can draw a similar correlation to the debate currently raging over the use of marijuana…

There’s no denying that pot has the reputation of mellowing people out. Most users report that pot sedates them, making it less likely to cause violence than substances such as alcohol or stimulants (like cocaine and methamphetamine). But there are some conflicting reports. For some users, pot can cause fear, anxiety, panic, and even paranoia-and that can lead to aggressive behavior. But even in those cases (fortunately!), their behavior improves once the paranoia and anxiety wear off.

What the Studies Say

As we know by now, the trouble with understanding the issues is the lack of ongoing research that has been conducted due to pot’s classification as a schedule 1 drug. When it comes to the issue of violence, there are also our preconceived ideas to wrestle with. If you asked your friends or colleagues whether they think pot leads to violence, most people would likely fall back on the idea of what it is to be “stoned.” And most of us don’t think that looks like a drug-fueled rampage.

That’s the kind of thinking that might stop us from asking important questions. Alex Berenson is a former reporter for the New York Times and the author of Tell Your Children: The Truth about Marijuana, Mental Illness, and Violence. His perception had been that pot was a relatively benign substance-until his wife, a psychiatrist who treats mentally ill criminals, made an off-hand comment one day after work. She stated that all the violent criminals she sees had been pot smokers before they were incarcerated. Their conversation sparked Berenson’s research into the matter. In the course of that research, he looked at the link between marijuana and mental illness. He also researched whether the delusions and paranoia that go along with pot and mental illness can trigger violence.

One study he looked at came from a 2013 paper about a survey of 12,000 American high school students published in the Journal of Interpersonal Violence. It showed that those who used only marijuana were three times more likely to be physically aggressive than abstainers were; those who used only alcohol were 2.7 times more likely to be aggressive. Of course, this survey doesn’t establish that marijuana causes violence, but it does show a correlation.

Berenson also looked at the statistics from Washington, the first state to legalize marijuana. Between 2013 and 2017, the rate of aggravated assault rose 17 percent and the murder rate rose 44 percent (both statistics are at least twice the nationwide rate of increase). Again, this doesn’t establish any causation, but it does show additional correlation.

A study in the Journal of Psychological Medicine reported on the the Cambridge, England Study in Delinquent Development, which looked at 411 boys who were born around 1953 and lived in working-class neighborhoods of London; the study followed its subjects for 50 years. A full 97 percent of the subjects were Caucasian and all of them were raised in two-parent households. The researchers considered antisocial traits, alcohol use, other drug use, cigarette smoking, mental illnesses, and family history. More than a fifth (22 percent) of the pot smokers reported violent behavior that began after initiating their use of pot, whereas only 0.3 percent reported violence before using weed. Use of cannabis over the lifetime of the study was the strongest predictor of convictions for violent behavior, even when the other factors that contribute to violent behavior were considered in the statistical analysis. The authors suggest that marijuana use may impact neurological circuits that control behavior, which may lead to impulsive, violent behavior. More research is needed, particularly research that attempts to look at causation.

Withdrawal Can Trigger Problems

When considering whether pot leads to violent behavior, it’s worth keeping in mind that people may experience some troublesome withdrawal symptoms when they stop using. Those symptoms can include trouble sleeping, irritability, anxiety, and loss of appetite. Any of these symptoms can trigger an emotional response, depending on personality and other factors. But withdrawal can definitely lead people to lash out and engage in aggressive behavior. It’s just a potential effect of pot usage.

The Upshot

The research indicates that for the majority of people, marijuana does not trigger violent behavior. It truly is a drug that makes you mellow. Some people use it to help with insomnia, others find it helpful with their anxiety. But for a small but significant subset of people, marijuana use leads to anxiety, paranoia, and even violence. That outcome is an outlier, but the outliers can’t be ignored simply because they are not the norm. Two issues are in play here: (1) More and more people are smoking marijuana. (2) Marijuana has become increasingly potent over the years. Both of these facts mean that we can’t just ignore the fact that there may be a link between marijuana and violence as more research is done.

Bottom Line for Morality: The message of pot’s potential to enhance or even trigger violent behavior needs to be more broadly made known so that people with a known propensity to anxiety, panic or paranoia can make more informed choices on pot use.

Bottom Line for Investing: The issue of pot as a potential trigger for violence clearly lands in the negative column. But it is more of a “tail issue”, meaning that if doesn’t affect the fat part (or vast majority) of the weed-using bell curve. Therefore, while important, it is not a broadly impactful issue that will tip the scale on pot investing.

Great trading and God bless you,
D.R. Barton, Jr.

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