In legalization-speak, 2016 will always be remembered as the year cannabis broke wide open.
While pot prohibition officially ended in 2012, when voters in Colorado and Washington said yes to legalizing and regulating recreational marijuana, that was only the beginning. Adult-use cannabis’ steady trickle continued in the 2014 election, when Oregon, Alaska and Washington, D.C. all joined the 420-friendly ranks.
But this year the legalization gates sprang open as eight of the nine states with marijuana measures on their ballots voted to legalize it — four on the retail side, four on the medical side.
As these states begin to write and implement their marijuana regulations, and as their predecessors continue to sell billions of dollars of heavily taxed legal cannabis annually, they’re doing so in something of a public health vacuum. What does legal marijuana mean for the long-term health of our communities?
We still don’t know.
In these still-early days, there’s still more we don’t know about cannabis and its components’ complicated relationship with our bodies and minds than what we do know. With other recreational substances, alcohol and tobacco included, we have reams of top-level public health research — studies that dissected the habits of tens of thousands of Americans, giving scientists an accurate, big-picture focus on those drugs’ impacts on our health.
With weed, that research has yet to be conducted. In fact, not a lot of research has been done to determine the medical efficacy of cannabis — primarily because of federal prohibition.
But that’s starting to change.
In 2016, we saw some important cannabis research published in top medical journals — research that flips the script on previously held beliefs and research that backs up what we’ve already seen anecdotally with medical cannabis.
And so here are some of the year’s most important scientific studies on cannabis.
Medical Marijuana Laws Reduce Prescription Medication Use In Medicare Part D, published in Health Affairs
As Kaiser Health News reported:
New research found that states that legalized medical marijuana — which is sometimes recommended for symptoms like chronic pain, anxiety or depression — saw declines in the number of Medicare prescriptions for drugs used to treat those conditions and a dip in spending by Medicare Part D, which covers the cost on prescription medications …
The researchers found that in states with medical marijuana laws on the books, the number of drug prescriptions dropped for treating anxiety, depression, nausea, pain, psychosis, seizures, sleep disorders and spasticity. Those are all conditions for which marijuana is sometimes recommended. Prescriptions for other drugs treating other conditions, meanwhile, did not decline.
Pot-Smokers Harm Gums; Other Physical Effects Slight, published in Duke Today
As The Washington Post reported:
Long-term marijuana use is not associated with a raft of physical health problems, according to a new study, with one surprising exception: gum disease.
Researchers led by Madeline Meier of Arizona State University tracked the marijuana habits of 1,037 New Zealanders from birth to middle age to see what effect those habits have on some common measures of physical health, including lung function, systemic inflammation, cholesterol levels, blood pressure, body weight, blood sugar and dental health.
What they found was surprising: After controlling for other factors known to affect health, especially tobacco use and socioeconomic status, marijuana use had no negative effect on any measure of health, except for dental health. People who smoked more weed had a higher incidence of gum disease.
Effects of Medical Marijuana on Migraine Headache Frequency in an Adult Population, published in Pharmacotherapy
As 7News reported:
Migraines can really hamper productivity when they strike but for the first time, Colorado researchers have proof that medical marijuana can help ease that dreadful pain.
“We were not expecting the decrease in frequency in migraine that we saw. It was pretty dramatic,” said Dr. Sarah Anderson with Skaggs School of Pharmacy at CU Anschutz.
Researchers at CU Anschutz looked at dozens of charts from patients treated at “Gedde Whole Health,” a private Colorado clinic that prescribes medical marijuana for a variety of ailments.
Of the 121 patients studied, 103 reported a decrease in their monthly migraines. To put it another way, the frequency of migraines dropped from about ten per month to less than five.
Subjective Aggression During Alcohol and Cannabis Intoxication Before and After Aggression Exposure, published in Psychopharmacology
As The Washington Post reported:
What about a link between marijuana use and aggression? Most pot smokers will tell you that marijuana helps them relax. The popular stereotype of a heavy marijuana user is the guy stoned out of his mind on the couch, eating Funyuns and watching cartoons.
But surprisingly, research on the link between marijuana and aggression has been mixed. Marijuana seems to make most people relaxed, but it can also cause anxiety and paranoia, conditions which can occasionally manifest themselves in violent ways. There are occasional reports out of Colorado of marijuana users causing harm to themselves or to others.
So a recent study from the Netherlands, published in the journal Psychopharmacology, attempts to put this question to bed using the gold standard of scientific research: a random controlled trial. They recruited a group of 20 heavy alcohol users (3+ drinks a day for men, 2+ for women), 21 heavy marijuana users who smoked at least 3 times a week, and 20 controls who didn’t use either drug heavily at all.
They then got the alcohol users drunk until their BAC measured 0.8, the standard threshold for impairment. They got the marijuana users high, by dosing them with 300 micrograms of THC per kilogram of bodyweight delivered via a vaporizer. The control group didn’t get to do any of this fun stuff, because they were controls.
Then they made all three groups complete a number of tests designed to get people riled up. The first, known as the “single category implicit association test,” had people match positive and negative words to photos depicting aggressive and violent behavior — punching, kicking, etc. In the second test, respondents played a computer game in which they were told they could win money by pressing buttons. They were pitted against an adversary who could undermine the players by taking money from them. The players were unaware that the “adversary” was actually controlled by the computer.
The researchers measured aggression, before and after the respondents took the test, by asking them how aggressive they felt on a 100-point scale. For good measure, they had the marijuana and alcohol users go through the whole thing again one week later, this time without getting high or drunk, as a kind of separate control.
They found, first of all, that “alcohol intoxication increased subjective aggression in the alcohol group.” The alcohol users, in other words, acted more aggressive when they were drunk than they did when they were sober. By contrast, the smokers became less aggressive when they were high.
GW Pharmaceuticals Announces Second Positive Phase 3 Pivotal Trial for Epidiolex (cannabidiol) in the Treatment of Lennox-Gastaut Syndrome, not published
As The Cannabist reported:
Experimental marijuana-based drug Epidiolex significantly reduced convulsive seizures among epilepsy patients in a recent clinical trial, according to GW Pharmaceuticals, the U.K. company that makes the drug.
Among the drug’s primary ingredients is cannabidiol, better known as CBD, a non-psychoactive marijuana derivative that is anecdotally known for helping some patients suffering from epilepsy, Crohn’s and other diseases. There is little scientific evidence backing up patients’ experiences with CBD, which is one of the reasons GW Pharmaceuticals’ first-of-its-kind study is so important.
Epidiolex is being studied to treat Dravet syndrome, a rare type of epilepsy for which there are currently no treatments approved in the U.S. GW Pharmaceuticals is currently in talks with federal regulators, hoping that Epidiolex will be introduced to the U.S. market — which would make it the first prescription drug in America that is extracted from cannabis.
“The results of this Epidiolex pivotal trial are important and exciting as they represent the first placebo-controlled evidence to support the safety and efficacy of pharmaceutical cannabidiol in children with Dravet syndrome, one of the most severe and difficult-to-treat types of epilepsy,” Orrin Devinsky, M.D., of New York University Langone Medical Center’s Comprehensive Epilepsy Center and the trial’s principal investigator, said in a statement. “These data demonstrate that Epidiolex delivers clinically important reductions in seizure frequency together with an acceptable safety and tolerability profile, providing the epilepsy community with the prospect of an appropriately standardized and tested pharmaceutical formulation of cannabidiol being made available by prescription in the future.”