Frequent Cannabis Users Wake With Elevated Stress Hormone Levels, Study Finds

Adults who use cannabis frequently tend to have higher levels of the stress hormone cortisol immediately upon waking compared to non-users, according to new research published in the journal Cannabis. The finding suggests that elevated morning cortisol may serve as a biological marker for problematic cannabis use—though the overall daily rhythm of cortisol release appears similar between groups.

The study, conducted at Oregon State University's Substance Use & Neurocognition Lab, adds to a growing body of evidence examining how chronic cannabis consumption affects the body's stress response systems. Unlike some previous research suggesting that heavy cannabis use might blunt the morning cortisol spike, this investigation found that frequent users actually started their day with higher absolute cortisol levels, even if their thirty-minute post-waking increase followed a normal pattern.

The Cortisol Awakening Response

The human body manages stress through the hypothalamic-pituitary-adrenal (HPA) axis, a neuroendocrine system that coordinates chemical signals resulting in cortisol release. This hormone helps mobilize energy and respond to environmental demands. In a typical daily cycle, cortisol levels rise sharply within the first thirty minutes after waking—a phenomenon known as the cortisol awakening response that serves as a physiological indicator of how well the body prepares for the day ahead.

Repeated activation of the HPA axis from chronic stress or heavy substance use can cause physiological wear and tear, eventually disrupting natural rhythms. Such disruptions often accompany mental health challenges including anxiety and depression. Previous research into alcohol use disorder indicated that chronic substance consumption could blunt the morning cortisol spike, leading scientists to investigate whether cannabis produces similar effects.

Study Design and Findings

The research team recruited 82 adult participants, dividing them into two groups: 39 frequent cannabis users who consumed the substance at least three days per week over the past year, and 43 healthy controls who used cannabis no more than one day monthly. To isolate the effects of cannabis on stress hormones, the study excluded individuals with lifetime psychiatric diagnoses, severe medical conditions, or those taking psychotropic or steroid medications.

After laboratory screening to ensure participants were not acutely intoxicated, subjects completed assessments measuring sleep quality, depression, anxiety, and perceived stress. Frequent cannabis users also completed questionnaires evaluating negative consequences related to their consumption, such as social or occupational problems. Participants then collected saliva samples at home on two consecutive weekdays—immediately upon awakening, thirty minutes after waking, and at 9:00 PM—recording subjective stress levels with each sample.

Laboratory analysis revealed no statistically significant differences in the cortisol awakening response between groups. Both experienced similar relative increases in cortisol during the first thirty minutes after waking, and evening cortisol levels also showed no group differences. However, frequent cannabis users had higher absolute baseline cortisol levels at the exact moment of awakening.

Crucially, within the cannabis use group, elevated morning cortisol correlated not with the number of use days per month but with the severity of cannabis-related consequences. Participants experiencing more negative life impacts from their use—whether social, occupational, or health-related—showed the highest cortisol levels upon waking.

Interpreting the Results

The distinction between use frequency and use consequences represents a significant finding. It suggests that morning cortisol elevation may serve as a biological indicator of problematic marijuana dependence rather than mere regular use. This aligns with clinical frameworks that distinguish between use and harmful use, emphasizing outcomes over quantity.

Lead researcher Anita Cservenka noted that the findings could inform treatment efforts aimed at reducing negative consequences of cannabis use, potentially benefiting users' physiological stress systems in the process. For individuals whose cannabis consumption has begun affecting their functioning—interfering with work, relationships, or health—elevated morning cortisol may provide an objective marker alongside self-reported symptoms.

The study also found that higher self-reported stress correlated with higher cortisol levels across all participants during morning hours, though this association tended to be stronger in the control group. Exploratory analyses separating participants by sex indicated the stress-cortisol link was present in males but not statistically significant in females, though the smaller sample sizes in these subgroup analyses limit firm conclusions.

Limitations and Open Questions

As an observational study, this research cannot establish causation. It remains unclear whether frequent cannabis use directly increases basal morning cortisol levels, or whether individuals with naturally higher baseline cortisol are more drawn to heavy cannabis consumption as a coping mechanism for stress. The relationship likely involves complex bidirectional interactions over time.

The frequent cannabis users in the sample averaged roughly 25 years old compared to 21 for controls. While statistical models did not identify age as a driving factor for cortisol levels, age-related hormonal differences warrant consideration. The overall sample size of 82 participants, while adequate for primary analyses, provided limited power for sex-specific exploratory analyses.

Future longitudinal research tracking individuals before and after they initiate cannabis use will be necessary to determine whether stress system alterations represent predisposing factors for frequent use or consequences of chronic consumption. Such studies could help clarify the temporal dynamics of the cannabis-stress relationship and inform prevention and intervention strategies.

Implications for Users and Clinicians

For regular cannabis users, the findings suggest that monitoring how their use affects life functioning—not just how often they use—may provide important insights into their relationship with the substance. Elevated morning stress, whether measured through cortisol testing or simply noticed as feeling more stressed upon waking, could signal that use patterns have shifted toward problematic territory.

For clinicians, the research adds to evidence that marijuana dependence involves measurable biological changes, not merely behavioral choices. Integrating biomarkers like cortisol into assessment protocols could enhance identification of individuals who might benefit from intervention, particularly those who may not recognize or report the negative impacts of their use.