cannabis cortisol appears higher at waking among frequent cannabis users, according to an Oregon State University study that measured morning cortisol patterns. The study, published in the journal Cannabis and led by Anita Cservenka of OSU’s College of Liberal Arts, found that people who use cannabis often start the day with more circulating cortisol than nonusers, while the typical morning rise in cortisol (the cortisol awakening response, or CAR) was similar between groups.
Researchers focused on the hypothalamic-pituitary-adrenal (HPA) axis, the neuroendocrine system that governs hormonal responses to stress. They measured cortisol immediately on waking and again about 30 minutes later. CAR is calculated by subtracting the waking cortisol value from the 30-minute value; it is commonly used as a marker of how the body prepares for daily demands. In this study, CARs were comparable for frequent users and nonusers, but the baseline cortisol measured right after waking was higher in frequent users.
OSU scientists note the finding does not demonstrate cause and effect. “We would need to study the same groups of people over a longer period of time to understand any cause-and-effect relationship, but we think this provides an important starting point,” Cservenka said. The team includes coauthors Julia Donner and Alexia Obrochta.
Why cortisol matters Cortisol is produced in the adrenal glands and helps regulate blood pressure, blood sugar, immune responses and metabolism. The hormone rises during acute stress to help the body respond and recover. Short-term elevations in cortisol are adaptive; sustained high cortisol over weeks or months is linked to increased risk of anxiety, depression and cardiovascular disease.
The study frames higher waking cortisol as a possible marker of disrupted daily stress rhythms among frequent cannabis users. Cservenka said, “Our research suggests cortisol levels upon awakening may serve as a neurobiological marker of problematic cannabis use, and that connection needs to be investigated further.” The authors also noted that prior studies reported a blunted CAR in frequent users; the present study did not replicate that result, suggesting analytic choices and sample differences can change outcomes.
Population context and usage trends The researchers highlighted U.S. usage trends that make the question relevant for public health. National survey data show 29% of adults ages 19–30 reported cannabis use in the previous 30 days — nearly double the rate from 15 years ago. More than 10% of that age group reported using cannabis 20 or more times in the prior 30 days, a figure more than twice what was reported 15 years earlier. The authors connect those patterns with concerns about stress-motivated and problematic use: stress is a common reason people use cannabis, and people with higher stress may use more often.
Possible directions and limitations The OSU team emphasizes that cross-sectional measurement cannot determine whether frequent cannabis use raises waking cortisol, whether higher waking cortisol predisposes people to use cannabis more often, or whether a third factor drives both. The authors call for longitudinal studies that follow the same people over time and, where ethical and feasible, controlled experiments to test causality.
The study contributes a specific finding: frequent users had higher absolute cortisol levels at awakening, while the 30-minute rise (CAR) was not reduced. That pattern implies altered baseline HPA activity rather than a change in the short-term morning surge. The researchers note that analytic strategy, sample selection (age range, frequency definitions) and timing of measurements can affect results; earlier reports of a blunted CAR in frequent users may reflect those differences.
Clinical and public-health implications If higher waking cortisol reliably associates with frequent, heavy cannabis use, clinicians and researchers could use morning cortisol as one measurable biological marker when assessing problematic use in young adults. Elevated morning cortisol also has known links to mood and cardiovascular outcomes, which suggests potential downstream health concerns if elevated levels persist. However, the authors stop short of recommending clinical screening based on this single study.
The team points to a plausible behavioral feedback loop: dysregulated stress systems might motivate more frequent cannabis use for short-term relief, while repeated heavy use could further disrupt HPA regulation. Testing that loop requires repeated measurements and interventions over months or years.
What to watch next Researchers should track individuals across time, measure cannabis frequency and amount precisely, control for sleep patterns and other stressors, and examine whether changes in use patterns predict changes in waking cortisol. Studies that include diverse age groups and control for tobacco, alcohol and other drug use will clarify whether the cortisol differences relate specifically to cannabis.
For now, the OSU study adds a measurable physiological correlate — higher morning cortisol — to the profile of frequent cannabis use in young adults, and it frames specific, testable questions for future research about stress biology and substance use.
