In the US, marijuana is our most commonly used illicit drug. Anxiety is our most common mental disorder. Yet the relationship between the two has received scarce attention from researchers.

Perhaps the lack of analysis stems from what’s assumed as a clear-cut association. Most cannabis users will claim that marijuana is an antidote to anxiety and a perfect solution to stress. This laid-back conception has followed the drug around endlessly, reinforced by carefree pop culture potheads like “The Dude” in The Big Lebowski or Cheech and Chong in their cult-classic films .

And although one in eight Americans use marijuana for mental relaxation, many have found that weed doesn’t help them unwind. Quite the contrary, some people lose their shit on pot.

Cannabis-induced anxiety can be innocuous, causing some mild paranoia that you’re able to talk yourself out of. But it can also become overwhelming, producing panic attacks that leave you in the fetal position, feeling helplessly out of control.

A similar traumatic episode transpired for Simon, a business-owner in Boulder, CO, and convinced him to give up cannabis forever. “I used to smoke all day, every day,” Simon explains, “until a terrible panic attack left me unable to get high again without getting extremely anxious.”

Simon was simply smoking and playing video games with friends when his eyesight started wavering. His heart began beating rapidly, he was breathing heavily but never getting enough air, and a powerful paranoia suddenly set in. “I felt like my health was rapidly declining,” he says. “I became convinced I was having a heart attack or a stroke, and I kept telling myself, ‘This is where it all ends.’”

But of course, it didn’t all end for Simon. His panic attack only brought an ending to his peaceful state of mind and easygoing experiences under the influence of marijuana.

Some studies have documented the common correlation between anxiety afflictions and cannabis. The most cited research on the subject finds that cannabis can cause intense fear and anxiety, and especially in higher doses, panic and phobic attacks. This study also reinforces existing literature in asserting that anxiety reactions and panic attacks are actually the acute symptoms most frequently associated with cannabis use.

This shouldn’t be surprising. Our brains are extremely complex machines. When marijuana tinkers with our brain’s chemistry, we’re all liable to have drastically different responses.

When you take a hit, the weed stimulates your ECS (endocannabinoid systems), the noodle department that regulates your responses to rewards, stress and fear. When THC slips into your brain’s ECS, its normal balance gets all out of whack, which can fuck with your ability to properly respond to stress.

This effect is prevalent among new cannabis users, but it can also take hold over even seasoned smokers. Stoners become especially susceptible to anxiety and panic attacks when consuming higher doses, as evidenced by innumerable stories of smokers who eat a super-potent edible and end up calling 911 because they’re convinced they’re dying.

Marijuana is unique in that it has opposite effects depending upon the dosage. In small doses, THC can relieve anxiety in some users, yet induce mild paranoia or social anxiety in others. In large quantities, however, these awful frantic side effects are usually exaggerated, no matter how much of a tolerance you think you’ve established.

Yet, if you’ve had a marijuana meltdown (or several) and don’t think inexperience or a large dosage is to blame, it’s possible that you’re simply genetically predisposed to that kind of reaction. In fact, one out of five people are far more likely to experience anxiety with cannabis as a result of their brain chemistry. Even those who once smoked like a fiend can develop new mental responses to marijuana over the course of their life.

In any case, the extensive stereotype that marijuana is the elixir of anxiety isn’t entirely accurate. We all know a few friends who can’t handle their weed, and their adverse reactions are, according to the few studies we have, far more frequent than we formerly thought.

Sometimes, no matter the strain, the dose, or the stress-free environment, marijuana is not your way to unwind. And even if you won’t take a toke, we’re sure your bud-loving buddies will love you either way.