Pilot Study of Cannabis Use Reduction and Associated Functional Outcomes.

Beckham J.; Hicks T.; Calhoun P.; Dennis M.; Kirby A.; Hertzberg J.; Dennis P.; Budney A.; Kimbrel N. · International journal of addiction nursing · 2026

**Background & Methods** This randomized controlled trial enrolled 59 individuals with heavy cannabis use to evaluate whether cannabis use reduction (rather than complete abstinence) produces meaningful functional improvements. Participants were randomized to mobile contingency management (mCM) intervention or yoked control, completing 2 weeks of baseline ecological momentary assessment (EMA) followed by a 6-week reduction period, with repeated daily biological verification via videotaped saliva testing (2-3 times daily). **Key Findings** • Participants in the mCM intervention demonstrated statistically significant improvements in drugged driving behavior and working memory compared to controls, despite continued cannabis use rather than abstinence. • Results for positive affect, negative affect, and pain outcomes were inconsistent and less conclusive across groups. • No significant changes were detected in physical activity levels between intervention and control groups over the study period. **Dosage & Administration** Not reported. The study focused on frequency and quantity reduction rather than specific dosing parameters. **Safety & Adverse Effects** Not reported. The abstract does not describe adverse events or safety outcomes associated with the intervention or cannabis use patterns. **Evidence Quality** This pilot RCT represents among the first evidence that significant cannabis use reduction—without achieving abstinence—can produce short-term functional benefits. However, several limitations warrant consideration: the relatively small sample size (n=59), short study duration (8 weeks total), and limited follow-up period may have constrained detection of longer-term functional changes. The mixed results across outcome domains (clear benefits for drugged driving and working memory; unclear for affect and pain) suggest variable treatment effects. The use of EMA and frequent biological verification strengthens internal validity, though generalizability to broader cannabis use populations remains unclear. The study design does not establish mechanisms underlying observed improvements or identify which patient characteristics predict functional gains from reduction-based interventions. These findings suggest that harm reduction approaches merit further investigation as alternatives to abstinence-focused treatment, but larger, longer-duration trials are needed to establish clinical significance and durability of benefits.

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