Quantity of delta-9-tetrahydrocannabinol consumption and cannabis use disorder among daily cannabis consumers.

Background and Aims: Amid escalating cannabis legalization and daily consumption in the United States (US), determining the risk of cannabis use disorder (CUD) and relevant consequences among daily consumers has become a public health priority. Understanding these risks requires valid assessment of the daily quantity of delta-9-tetrahydrocannabinol (THC) consumed and its relation to consequences. This study characterized daily cannabis consumption using a new method for estimating milligrams of THC (mgTHC), and examined the relationship between daily mgTHC and CUD severity in a large national sample of daily consumers.
Design, Setting and Participants: US adult (aged 18+ years) daily cannabis consumers (n = 4134) completed a comprehensive online survey of cannabis consumption patterns (e.g. frequency, quantity, product types, potencies, administration methods) and Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) CUD criteria.
Measurements: The primary exposure was past-week daily mgTHC consumption, calculated from survey responses to queries about product type, amount and potency consumed and including adjustments for puff size and loss of THC from specific methods of administration. The primary outcomes were (1) number of CUD criteria (range = 0-11) and (2) CUD severity categories: none, mild, moderate, severe.
Findings: Median daily consumption was ~130 mgTHC, with substantial variability (25% ≤ 50 mg and 25% ≥ 290 mg). On average, participants endorsed 2.5 CUD criteria, and 65% met criteria for CUD (39% mild, 18% moderate, 8% severe). Greater daily mgTHC predicted higher CUD criteria count [beta _log(mgTHC)  = 0.50, 95% confidence interval (CI) = 0.267-0.734] and higher odds of mild [log odds ratio (logOR) = 0.238, 95% CI = 0.184-0.292], moderate (logOR = 0.303, 95% CI = 0.232-0.374) or severe (logOR = 0.335, 95% CI = 0.236-0.435) CUD.
Conclusions: Among daily consumers of cannabis, there appears to be a positive relationship between the daily quantity of cannabis consumed (measured in milligrams of delta-9-tetrahydrocannabinol) and both the risk and severity of cannabis use disorder.
(© 2024 Society for the Study of Addiction.)