Subjective Stress and Diurnal Salivary Cortisol in Adults with Frequent Cannabis Use

Abstract

Objective: The hypothalamic-pituitary-adrenal (HPA) axis, the major neuroendocrine system that responds to stress, may be dysregulated by substance use. The rise of cortisol in the morning, known as the cortisol awakening response (CAR), is believed to be a reliable marker for individual differences in HPA axis activity. The purpose of this study was to investigate differences in the CAR between individuals with frequent cannabis use (CU) and healthy controls (HC) and determine whether cannabis use status moderates the relationship between subjective stress and cortisol levels. Method: 39 CU and 43 HC reported subjective stress levels and collected daily saliva samples at awakening, 30 minutes later, and in the evening, on two consecutive weekdays. We examined group differences in the CAR (30 min post awakening – awakening cortisol), and the association between stress and cortisol levels at each collection time with group entered as a moderator in regression analyses. Results: There were no significant group differences in the CAR (p = .23). At awakening, subjective stress was positively related to cortisol levels (p = .001) and CU had higher cortisol than HC (p = .047), which was significantly related to consequences of cannabis use (p = .007). Conclusions: While the rise of the CAR did not differ between groups, individuals with frequent cannabis use exhibited significantly higher basal cortisol levels at awakening. This elevation was positively correlated with cannabis-related consequences, suggesting that awakening cortisol may serve as a neurobiological marker of problematic cannabis use and warrants further investigation.