Behavioral economic cannabis demand following recreational cannabis legalization: Six-year findings from an observational cohort study of community adults in Canada.

Coelho S.; Keough M.; MacKillop J. · Drug and alcohol dependence · 2026

**Background & Methods** This observational cohort study examined intraindividual changes in cannabis demand (a behavioral economic measure of relative reinforcing value) over six years following recreational cannabis legalization in Canada. Community adults (n=1,103) completed cannabis demand assessments across 14 waves from September 2018 to April 2025 (median retention 86.86%), with multilevel growth models used to analyze trajectories overall and stratified by pre-legalization use frequency, sex, and age. **Key Findings** - Contrary to hypotheses, all cannabis demand indices significantly decreased over the six-year post-legalization period despite cannabis consumption remaining relatively stable, suggesting increased availability paradoxically reduced cannabis's reinforcing value in the general population. - Pre-legalization use frequency moderated trajectories: participants actively using cannabis pre-legalization showed declining demand with steeper declines associated with higher pre-legalization frequency, while non-users demonstrated stable or increasing demand patterns. - Sex differences emerged in demand trajectories, with males exhibiting steeper declines in intensity, Omax (maximum expenditure), and breakpoint (price resistance) compared to females. **Dosage & Administration** Not reported. **Safety & Adverse Effects** Not reported. **Evidence Quality** Strengths include a large community sample with high retention (86.86%), longitudinal design with 14 assessment waves over six years, and sophisticated multilevel modeling to capture intraindividual changes. Limitations include reliance on a nonclinical community sample that may not generalize to clinical populations or vulnerable groups; lack of specificity regarding cannabis potency, product types, or consumption routes; absence of data on concurrent substance use, mental health outcomes, or socioeconomic factors; inability to establish causality despite the observational design; and potential selection bias in cohort composition. As an observational cohort study, this represents moderate-quality evidence. The divergence between stable consumption and declining demand warrants further mechanistic investigation and replication in diverse populations, particularly among individuals with cannabis use disorder or other high-risk groups.

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