By Ben Adlin

Cannabis won’t make you a nervous, miserable wreck. That’s the conclusion of a study published Thursday in the journal JAMA Psychiatry that failed to find a connection between mood disorders and cannabis use in adults. Researchers looked at about 35,000 U.S. adults, examining their cannabis use and, three years later, looking at their rates of mental illness. The conclusion: “Cannabis use was not associated with increased risk for developing mood or anxiety disorders.” Case closed? Not quite. Some other recent studies suggest such a connection might exist, though none has established a causal connection. Expect the back-and-forth to go on for a while. (Research would, of course, be easier if the federal government simply rescheduled cannabis, but you already know that.) The study did find an association between cannabis use and substance-use disorders, however, so there’s still good reason to consume responsibly.

Are more people using cannabis? Probably, but not as many as we thought. A study back in October said the number of people using cannabis more than doubled from 2001 to 2013, but a new report raises doubts. Instead of an increase in consumption, researchers wrote in the journal JAMA Psychiatry, it’s more likely the observed spike reflects simply an increased willingness by survey respondents to acknowledge their use. The update hinges on the fact that the initial survey was based on face-to-face interviewers with researchers. As society has become more accepting of cannabis, the new study found, respondents were less likely to conceal their use of the drug. Controlling for the difference, researchers revised the initial study’s estimate and found that cannabis use between 2001 and 2013 increased by a far more modest 19 percent.

Can cannabis help with your cardio? Believe it or not, yes. The little available research we have suggests cannabis is an “ergolytic,” meaning it decreases work capacity and cardiac output. But there’s more to a workout than peak horsepower. Iñigo San Millán, a director of sports performance at the University of Colorado, says cannabis can take the mind off pain and help athletes stay in the zone during tough workouts. It can also reduce stress and promote sleep, he says, making it a promising post-workout recovery aid. There are downsides, of course — cannabis can slow reaction times and may temporarily increase heartrate — but Clifford Drusinky, an elite triathlete, swears by the 20 milligrams of THC he eats in a cannabis-infused energy bar every morning: “Marijuana relaxes me and allows me to go into a controlled, meditational place,” he says. “When I get high, I train smarter and I focus on form.”

So maybe we should let athletes use it. The Super Bowl gave a whole bunch of former football players a chance to talk about how physically demanding (read: tragically devastating) the sport can be. It also let them tear into the NFL and its continued prohibition of cannabis, arguably one of the most promising treatments for a number of football-related injuries. Cannabidiol (CBD), for example, can help protect and even heal the brain. That could be big in a league where 96 percent of players, according to a 2015 study, show signs of chronic traumatic brain injury. Medical marijuana could help manage the pain of chronic traumatic encephalopathy and even slow the disease’s progression. It could also be far safer to players than prescription painkillers and other dangerous drugs. Nevertheless, NFL players even in legal states face fines and other penalties if they test positive for cannabis.

Elizabeth Warren is on board. The senator from Massachusetts urged the Centers for Disease Control and Prevention to consider cannabis as an alternative to painkillers, arguing that legalization could help end America’s opioid epidemic. Cannabis, after all, is effective at treating pain, it’s safe (aside from a few “non-serious” side effects), and it’s less likely to be used alongside alcohol or other painkillers. All that saves lives: States with medical marijuana laws have a 24.8 percent lower rate of opioid overdose deaths compared to states without medical marijuana, a 2014 study found. Another study last year noticed a 15 to 35 percent drop in substance abuse admissions — and a similar drop in opiate overdose deaths — in areas where dispensaries exist.

No breathalyzer for cannabis yet. Blame it on the molecules. NPR explains why it’s so much more difficult to design a breathalyzer for THC than it is for alcohol, and it mostly boils down to this: THC dissolves in fat, and booze dissolves in water. When you drink, alcohol saturates your body evenly, so the percentage in your breath is a good indicator of the percentage in your blood. But THC, being fat-soluble, collects in fatty tissues over time. The upshot? Alcohol behaves much more predictably and uniformly from person to person than THC, making it easier to test for and to correlate with impairment level. Despite efforts to develop a cannabis breathalyzer or saliva test, nothing so far has stuck. Play it safe and drive sober.

“This is your brain on drugs”? Not quite. Two separate studies this month fired back against the stupid-stoner stereotype and found no evidence adolescent marijuana use leads to a decline in intelligence. But it’s clear there’s still a lot to learn about the effects of cannabis on young brains. Another study found that participants who smoked cannabis daily as teenagers had lower verbal memory scores than those who used cannabis less frequently or began at a later age. Despite the apparent connection, however, the study found that past cannabis use did not appear to affect participants’ other cognitive functions.

It actually might help your head. Cannabis has long been used for the treatment of migraines, and a University of Colorado study published last month backs the practice up with data. Of 121 adult participants, about 85 percent reported having fewer migraines per month when using cannabis. The average number of migraines fell from 10.4 per month to 4.6, and only 2 percent saw an increase in migraine frequency. It’s still not clear exactly how cannabis curbs the headaches, but it’s increasingly clear that it does.

Scientists are homing in on genetic differences in cannabis users. Researchers at the University of Exeter and University College London identified a gene they say predicts how susceptible cannabis users are to developing mental illness. Doctors have been probing the connection between cannabis and psychosis for some time, but they’ve struggled to understand how one affects the other. The study found that young people with a particular variant of the AKT1 gene were more likely to demonstrate “psychotic-like” effects after using cannabis. Scientists had already established a link between the AKT1 gene and psychosis, but this was the first that showed a link between the gene and psychotic effects of cannabis. The researchers stressed psychosis was extremely rare, affecting only about 1 percent of users.

What’s going on in that bong? Is all that gurgling actually making your toke any healthier? We at Leafly weren’t too sure, so we found out. What did we find out? Nobody else is too sure, either. Filtering smoke through water does seem to remove a lot of the bad things in smoke, but it also removes a lot of the desirable cannabinoids. Dig into the research and there’s evidence both ways. The conclusion? While your bong might give you nice smooth hits, it ultimately may not be any healthier than a joint.

And finally, remember that DEA agent who warned medical cannabis might lead to stoned bunnies? Turns out there’s no scientific evidence for that. The DEA finally replied to a Freedom of Information Act Request about the claim by acknowledging that “no responsive records were located.” Are we relieved? Yes. Heartbroken? That, too. Stoned bunnies sound freaking adorable. But in case you’re wondering, scientists have tried to get rabbits high. Because science.

To continue reading this story, visit our friend’s website (opens in a new window):: Leafly Science Roundup: Can Cannabis Improve Your Workout?