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.

Grant Number: 3R01DA056371-04S1
NIH Institute/Center: NIH
Principal Investigator: JENNIFER BAILEY