Cannabis Legalization a Decade Later: A Longitudinal Study of Teens, Young Adults, and Parents in Washington State - Project Summary/Abstract We request a two-year administrative supplement to R01DA056371 (Cannabis Legalization a Decade Later: A Longitudinal Study of Teens, Young Adults, and Parents in Washington State; Bailey, PI), a longitudinal study of the long-term impact of nonmedical cannabis legalization on substance use patterns among 426 families (426 offspring, 846 parents/caregivers). We propose to use geographical information system (GIS) data to examine links between changing cannabis retail market characteristics in respondents' neighborhoods (retail outlet density, cannabis product prices, sales revenue, availability of high-potency products, local retail regulations) and the longitudinal course and characteristics of cannabis use. Decades of research on tobacco and alcohol markets show that regulating retail markets (e.g., restricting prices, products sold, and retail licenses) can reduce access, use, and harms for both youths and adults. Despite the spread of cannabis retail outlets, research examining the effects of establishing cannabis markets remains in its infancy. Studies assessing impacts of local cannabis retail market characteristics beyond outlet density and proximity are needed, as are studies including outcomes beyond use frequency and norms. Longitudinal studies assessing the impact of various characteristics of cannabis retail markets also are needed to guide regulatory and environmental interventions to minimize health-risking cannabis use behaviors linked to establishment of legal cannabis sales. We seek to collect and geocode cannabis market data in 2023, 2024, and 2025 and link it with 1) similar GIS data collected under prior funding in 2015-2017 and 2) adult and youth self-report survey data being collected in the parent project. The proposed 2023-2025 GIS data collection, together with existing data, will yield 6 waves of GIS data linking participants' residential addresses to neighborhood cannabis retail market characteristics across the first decade since the legal market was established (in 2014). The proposed supplemental activities provide a unique opportunity to examine prospectively how retail market characteristics affect cannabis use behaviors among youths and adults over time. Aims align with NIDA's strategic goal to improve understanding of the real-world landscape of drug policies, including cannabis legalization and commercialization. Although current funding covers the cost of the activities of the parent grant, accomplishment of the proposed aims is beyond re-budgeting. The proposed aims, which are tightly focused on changing cannabis market characteristics (i.e., commercialization), are within the scope of but do not overlap the aims of the parent project, which focus more broadly on the passage of nonmedical cannabis legalization. Findings will inform the development of cannabis market regulation policies that minimize underage and health-risking cannabis use behaviors.
