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Detecting cannabis use reduction through biochemical verification of urinary cannabinoids: An aggregated analysis of cannabis use disorder treatment trials examining average reductions and individual cut‐points

Year: 2025

Type: article

Abstract: BACKGROUND AND AIMS: Currently, there is no data-driven cannabis reduction metric using biochemical verification, which represents a significant gap in cannabis harm reduction research, treatment and policy. Using aggregated data from 7 cannabis use disorder treatment trials, the aims of this analysis were to 1) determine if decreases in self-reported cannabis use correlate with a decrease in urinary cannabinoids and 2) determine the cut-off in reduction of creatinine-normalized cannabinoids (CN:THC) associated with self-reported cannabis use reduction. DESIGN: Exploratory aggregated analysis of 7 cannabis use disorder treatment trials. SETTING: Individual studies were conducted in academic medical centers and community substance use treatment settings in the United States and led by investigators at the Medical University of South Carolina. PARTICIPANTS: Participants were included who had cannabis use data available through week 6 of study treatment and did not meet criteria for continuous cannabis abstinence (n = 471/920; 51%; analytic sample was 31% female; 67% White; 11% Hispanic; mean age of 25). MEASUREMENTS: Weekly self-reported cannabis use (days of use, sessions or grams of use per day, collected via daily diaries or timeline follow-back) and urinary cannabinoids [tetrahydrocannabinol (THC) metabolites; ng/ml]. The sample was categorized as 1) reduced self-reported cannabis use (50% reduction in frequency and/or 75% in amount; n = 220) or 2) no self-reported cannabis reduction (n = 251). Longitudinal models included indicators for reduction group, parent study, study week, baseline urinary cannabinoids and covariates (age, race, years of cannabis use) statistically significantly associated with study outcomes. FINDINGS: Participants self-reporting cannabis use reduction had statistically significantly lower urinary cannabinoids compared with those who did not reduce [Δ between groups = 391 ng/ml; 95% confidence interval (CI) = 231-551; P < 0.001]. Average urinary cannabinoids decreased by up to 50% from baseline levels for the cannabis reduction group. The classification model for decrease in urinary CN:THC did not produce a cut-point statistically significantly different from zero (-39.9; 95% CI = -70.3 to 2.9). CONCLUSIONS: Average urinary cannabinoids, measuring THC, during cannabis use disorder treatment trials appear to differ between participants with and without self-reported cannabis use reduction. Urinary cannabinoids appear to decrease concurrently with self-reported use reduction, with a 50% average decrease being observed among those self-reporting reductions. Overall classification models did not yield a urinary creatinine-normalized cannabinoids cut-off that could be used for individuals to detect meaningful cannabis reduction. Individual-based biochemical verification of cannabis reduction will require further work to establish, though average reductions of at least 50% in urinary cannabinoids may be a useful metric for the majority of those with cannabis use disorder in clinical and research settings.

Source: Addiction

DOI: 10.1111/add.70291