Cannabis prohibition hurts everyone. It hurts patients. It hurts taxpayers. It even hurts the cops who have better things to do with their time. And according to one scientist, prohibition kills just as many people in America as "drunk driving, homicide, or fatal opioid overdose."

Thomas Clark, PhD, is a physiology professor at Indiana University. Last month, he released a paper that compiled data from hundreds of peer-reviewed studies. These studies assessed pot as a treatment for conditions like cancer, diabetes, Alzheimer's, and obesity. He found, in practically every case, that cannabis could reduce the chance of premature death.

"Just looking at the effects of medical cannabis on physical health," Clark says over a phone call with MERRY JANE, "[it] seems to be reversing some of harms caused by the Western diet, which is deficient in certain things, and leads to metabolic syndrome and all sorts of issues. The biggest effects I saw were with conditions tied to obesity and metabolism."

One of the Western diet's major deficiencies is omega-3 fatty acids. Omega-3s are the heart-healthy molecules found in foods like fish, avocados, flax, kale, and olive oil. Doctors tell us to eat this stuff, but they rarely tell us why.

The secret: omega-3s are the precursors — or building blocks — for our body's "natural marijuana," the endocannabinoids. Endocannabinoids like anandamide and 2-AG behave much like the phytocannabinoids THC and CBD when they hit our cells' cannabinoid (CB) receptors. Endocannabinoids, just like the weed plant's phytocannabinoids, regulate our body's natural balance.

Of course, as it is in weed science, not everything is so cut-and-dry.

Last year, medical researchers led by Dr. Edison Manrique-Garcia at Sweden's Karolinska Institutet published a separate study that seemingly contradicts Clark's. The Swedish study concluded weed causes premature death, and it made headlines overnight.

So, what gives? How can these two papers draw such completely different conclusions?

To start, let's assume the Swedish study wasn't funded by prohibitionist agencies, and that the researchers followed stringent scientific protocols. Then, let's break it down: Manrique-Garcia's team pulled data from over 50,000 men — a rather hefty sample size — and they used government records to follow the subjects from their teen years until age 60. The Swedes discovered that "early" and "heavy" marijuana users were 40 percent more likely to die before reaching age 60 than subjects who did not use marijuana. They even controlled for other life-diminishing factors such as alcohol use.

Unfortunately, Manrique-Garcia's team could not be reached for comment. But Dr. Clark offered some possible reasons as to why the two papers do not necessarily contradict one another.

For starters, the Swedish study's conclusions come from "heavy" marijuana users: people who consumed cannabis more than 50 times over their lifespans. "A lot of studies have focused on those people — adolescents or very heavy users — and I don't know how representative they are of your typical user," explains Clark. "For instance, with alcohol, your typical alcohol user isn't drunk all day. I think there's something similar going on with marijuana."

Furthermore, the Swedish study did not identify how cannabis use led to premature death. The authors proposed that cannabis could trigger psychotic or suicidal thoughts in smokers, leading to higher premature death rates. Clark agrees that there is a link between psychotic behavior and cannabis use, but he stops short of saying weed causes people to go crazy.

"There've been several good studies about this," he says, regarding research that shows a link between pot and mental illness. "It's not yet clear to me how cannabis contributes, but their conclusions are that it's not cannabis causing this psychosis. It's that these people have an underlying risk factor."

The risk factor could be a host of maladies, such as personality or mood disorders like bipolar disorder, or post-traumatic stress disorder.

"There's similar studies with IQ and educational performance," Clark continues, "and they all sort of say the same thing: that there's a group of people who are at-risk, and these people are more likely to use cannabis at an earlier age."

In other words, since these individuals are already prone to risky behaviors due to mental illness, they tend to take on risky habits — like smoking weed where weed is outlawed. The risk-taking behavior precludes marijuana use, and would likely exist regardless of the individual's joint seshes.

Clark cites two studies to back up his claims. One is an Australian report that found cannabis dependency was typically a symptom of mental illness rather than the other way around. "Their concern was if you try to put someone into treatment to get them off of cannabis without addressing these associated mental health issues," he says, "then you'd have a poor outcome to get them off of cannabis."

The second study, published last year in Clinical Psychological Science, looked at the economics of cannabis dependence. The study discovered that "people with cannabis dependence, especially early, heavy cannabis users, showed a downward trajectory in socioeconomic outcome," Clark explains. "Basically, they have trouble holding down jobs, they don't have good-paying jobs, and there's very clear evidence this sort of socioeconomic effect can have negative consequences on longevity and health."

"These effects manifest at about 45 to 65 years old, which is about the same time period of the Manrique-Garcia study," Clark adds. "It's possible those subjects would have gone on an even deeper downward spiral without cannabis. And [the Swedish] paper did not adjust for socioeconomic status, I noticed, so right now that's my hypothesis for why they saw the pattern they did."

Given Clark's interpretation of the Swedish study, it appears prohibition does more than just prevent or dissuade people from accessing medical marijuana. Maintaining a severe social stigma on cannabis may also lead to incorrect treatments for mentally ill patients — by misleading therapists to single-out weed as the root cause behind someone's psychological issues.

Ironically, Clark's paper did address whether legal pot could prevent suicides: current research suggests legalization doesn't reduce suicides, but it doesn't cause an increase, either.

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