Addiction Science Made Easy
February 2022
CTN Dissemination Library
Abstinence has long been considered the target outcome for clinical trials testing the effectiveness of an intervention for substance use disorders. However, studies about cannabis have often struggled to achieve this standard.
Though reductions in use might be a better metric for cannabis-related studies, researchers haven’t yet determined how much of a reduction would be clinically meaningful when it comes to assessing whether or not an intervention has helped.
This study looked at two ways to measure cannabis use reduction: quantity (grams per using day) and frequency (days per week). Researchers defined high-, medium-, and
low-risk use for each system and tested them separately, then measured changes in risk level from baseline (BL) to end-of-treatment (EOL) for participants. They then looked at associations between the amount of reduction and improvements in anxiety, depression, and cannabis-related problems like issues at work or school, problems with friends or family, lack of energy, etc.
The study used data from the ACCENT study in the NIDA Clinical Trials Network, which evaluated the use of N-acetylcysteine (NAC) for adults with cannabis use disorder. Participants were 225 treatment-seeking adults (majority white males with a median age of 30.6 years old) who completed 12 weeks of treatment.
Analysis found that cannabis use risk levels are sensitive to reductions in cannabis use, and that risk reduction is associated with improvements in depression, anxiety, and cannabis-related problems. Importantly, the magnitude of risk reduction was associated with the magnitude of improvement – more reduction led to greater improvement.
Conclusions: This study has identified a useful way to capture reductions in use and risk during a clinical trial studying interventions for cannabis use disorder. Risk level reduction was associated with a range of functional improvements, suggesting that identifying risk levels and measuring the change in those levels over time might be a meaningful way to measure effectiveness for cannabis use disorder interventions. Given increasing access to cannabis worldwide, risk reduction approaches may be critical in reducing the public health burden of cannabis use disorder.