Researchers at Oregon State University have found that regular cannabis users wake up with elevated baseline levels of cortisol, the body's primary stress hormone. Published in the journal Cannabis, the study suggests that while cannabis is often used to unwind, chronic consumption may alter the body's natural stress response system.
The research team, led by behavioral neuroscientist Anita Cservenka, focused on the hypothalamic-pituitary-adrenal (HPA) axis. This system connects the brain and kidney glands to control cortisol release. Over time, consistently high cortisol levels can contribute to health issues, including anxiety and heart disease.
To measure this, researchers analyzed saliva samples from 39 frequent cannabis users (who consumed cannabis three or more nights per week) and 43 non-users. Participants collected samples immediately upon waking and 30 minutes later across two consecutive weekdays.
The study specifically tracked the cortisol awakening response (CAR)—the natural morning spike that prepares the body for the day. While both groups experienced a similar rise in cortisol during the first 30 minutes of waking, regular cannabis users started the day with a much higher baseline level of the hormone.
This elevated starting point suggests a potential disruption to the HPA axis. "Our research suggests cortisol levels upon awakening may serve as a neurobiological marker of problematic cannabis use," Cservenka noted, adding that the connection requires further investigation.
These findings contrast with a study from earlier this year, which suggested regular cannabis use blunts the morning cortisol spike. Cservenka explained that the discrepancy highlights the nuance in how cannabis affects the body, which may depend on sample sizes and testing methods.
The study highlights a growing public health concern as cannabis legalization expands. In the US, daily cannabis use now surpasses daily alcohol use, with 29% of young adults aged 19 to 30 reporting use in the past month, and over 10% using it 20 or more times a month.
- The research has been published in Cannabis.
