Characterizing Cannabis Use Reduction and Change in Functioning During Treatment: Initial Steps on the Path to New Clinical Endpoints

Reduction-based cannabis use endpoints are needed to better evaluate treatments for cannabis use disorder (CUD). This exploratory, secondary analysis aimed to characterize cannabis frequency and quantity reduction patterns and corresponding changes in psychosocial functioning during treatment. We analyzed 16 weeks (4 prerandomization, 12 postrandomization) of data (n = 302) from both arms of a randomized clinical trial assessing pharmacotherapy for CUD. Cannabis consumption pattern classes were extracted with latent profile modeling using self-reported (a) past-week days used (i.e., frequency) and (b) past-week average grams used per using day (i.e., quantity). Changes in mean Marijuana Problem Scale (MPS) and Hospital Anxiety and Depression Scale (HADS) scores were examined among classes. Urine cannabinoid levels were examined in relation to self-reported consumption as a validity check. Two-, three-, four-, and five-class solutions each provided potentially useful conceptualizations of associations between frequency and quantity. Regardless of solution, reductions in MPS scores varied in magnitude across classes and closely tracked class-specific reductions in consumption (e.g., larger MPS reduction corresponded to larger frequency/quantity reductions). Changes in HADS scores were less pronounced and less consistent with consumption patterns. Urine cannabinoid levels closely matched class-specific self-reported consumption frequency. Findings illustrate that frequency and quantity can be used in tandem within mixture model frameworks to summarize heterogeneous cannabis use reduction patterns that may correspond to improved psychosocial functioning. Going forward, similar analytic strategies applied to alternative metrics of cannabis consumption may facilitate construction of useful reduction-based clinical endpoints. Public Health Significance Statement This study examined different ways individuals might reduce the frequency and quantity of their cannabis use during treatment. Results suggest that specific patterns of cannabis reduction may be predictive of improved psychosocial functioning. The conceptual and analytic approach used in this study may help with the development of cannabis reduction-based endpoints for clinical trials.

Automated summary

Reduction-based cannabis use endpoints are important for evaluating treatments for cannabis use disorder (CUD). This study examined different patterns of cannabis reduction and their impact on psychosocial functioning during treatment. The findings suggest that specific patterns of cannabis reduction may be predictive of improved psychosocial functioning. The study's approach may aid in the development of reduction-based clinical endpoints for future trials.