Study links frequent cannabis use to elevated morning cortisol levels

When Anita Cservenka's team at Oregon State University measured cortisol levels in frequent cannabis users the moment they woke up, they found something consistent: these people started their day with more of the stress hormone already circulating through their bodies than people who didn't use cannabis regularly. The difference wasn't dramatic, but it was there, and it raised a question that researchers are only beginning to explore—what happens to your stress system when you use cannabis often enough that it becomes part of your daily routine?

Cortisol is the body's primary stress hormone, released by the adrenal glands when pressure arrives. In the short term, it's useful: it helps fight infection, stabilizes blood pressure, regulates blood sugar. But when cortisol stays elevated for long periods, the consequences accumulate. Anxiety, depression, heart disease—these are the costs of a stress system stuck in overdrive. The researchers focused on what's called the cortisol awakening response, or CAR, the natural rise in cortisol that happens in everyone during the first half-hour after waking. It's a marker of how well your body is preparing itself for the day ahead.

The study, published in the journal Cannabis and led by Cservenka with colleagues Julia Donner and Alexia Obrochta, measured cortisol right after participants woke and again thirty minutes later. The math is simple: subtract the first number from the second. Among both cannabis users and non-users, that rise looked similar. But the baseline was different. Frequent users simply woke up with more cortisol already in their system. Cservenka is careful about what this means. The research doesn't prove that cannabis use causes elevated morning cortisol, or that elevated cortisol drives people to use cannabis. Proving causation would require following the same people over years, watching how their cortisol and their use patterns change together. What this study does is point toward a connection worth investigating further.

The timing matters. Cannabis use among young adults has nearly doubled over the past fifteen years. Today, 29 percent of Americans between 19 and 30 report using cannabis within the previous month. More striking: over 10 percent of that age group use it twenty or more times in a single month—more than double the rate from fifteen years ago. These are not experimental users. These are people for whom cannabis has become routine. And stress, the researchers note, is often the reason people reach for it. Cannabis may offer short-term relief from pressure, but chronic use might be reshaping the very system designed to handle stress.

Cservenka suggests a troubling possibility: that a dysregulated stress system could create a cycle. If frequent cannabis use leaves you waking up with elevated cortisol, you're starting each day already primed for stress. That might push you toward cannabis again, looking for relief. The elevated cortisol upon waking could become a neurobiological marker of problematic use patterns—a physical signal that something in your stress response has shifted. Earlier research by other scientists found that frequent cannabis users showed a blunted cortisol awakening response, a flattening of that morning rise. Cservenka's team didn't replicate that finding, which suggests the picture is more complicated than it first appeared. Different studies, different methods, different populations—they're all finding slightly different pieces of the same puzzle.

What comes next is longer-term research, the kind that follows people over months and years, watching how their cortisol rhythms and their cannabis use evolve together. For now, the finding stands as an important starting point: frequent users wake up stressed, at least at the hormonal level, before their day has even begun.