After Washington legalized cannabis, marijuana use increased specifically among working 12th graders

While marijuana use decreased among younger Washington teens after legalization, use increased among working 12th graders relative to non-working peers, with stronger effects for those working more hours.

Graves, Janessa M et al.·The Journal of adolescent health : official publication of the Society for Adolescent Medicine·2019·Moderate EvidenceCross-Sectional
RTHC-02052Cross SectionalModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Between 2010 and 2016, marijuana use decreased among 8th and 10th graders regardless of work status. Among 12th graders, working youth showed significantly increased use relative to non-workers (AOR 1.34, 95% CI: 1.22-1.48). Youth in formal work settings (retail, service) were more likely to use than those in informal settings (babysitting).

Key Numbers

76,000+ students surveyed annually. Use decreased among working and non-working 8th/10th graders (2010-2016). Working 12th graders: AOR 1.34 (95% CI: 1.22-1.48) increase relative to non-working peers. Stronger associations with more work hours.

How They Did This

Difference-in-differences analysis using 2010 and 2016 data from Washington's Healthy Youth Survey (76,000+ youth annually), comparing marijuana use by work status and hours among 8th, 10th, and 12th graders in public schools before and after legalization.

Why This Research Matters

Working 12th graders represent teens with the most independence, disposable income, and exposure to adult environments where cannabis may be more accessible. This group may need targeted prevention as legalization creates new access pathways.

The Bigger Picture

The overall decrease in younger teen use is reassuring, consistent with other post-legalization studies. But the increase among working 12th graders suggests the workplace may be an important and overlooked access point for cannabis among older teens.

What This Study Doesn't Tell Us

Cross-sectional surveys at two time points cannot establish causation. Self-reported marijuana use. Cannot distinguish between legalization effects and secular trends. Work setting categories are broad.

Questions This Raises

  • ?Are working 12th graders accessing cannabis through adult coworkers?
  • ?Would workplace cannabis policies for employers of minors reduce this effect?
  • ?Do other states with legalization show the same pattern?

Trust & Context

Key Stat:
Working 12th graders: 34% higher marijuana use after legalization relative to non-working peers
Evidence Grade:
Moderate: large representative sample with difference-in-differences analysis, but cross-sectional design at two timepoints.
Study Age:
Published in 2019, comparing 2010 and 2016 data.
Original Title:
Employment and Marijuana Use Among Washington State Adolescents Before and After Legalization of Retail Marijuana.
Published In:
The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 65(1), 39-45 (2019)
Database ID:
RTHC-02052

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Did legalization increase teen marijuana use?

For younger teens (8th and 10th grade), use actually decreased after legalization in Washington. But among working 12th graders, use increased 34% relative to non-working peers, suggesting the workplace may be an access pathway for older teens.

Why are working teens different?

Youth in formal work settings like retail and restaurants were more likely to use marijuana than non-working youth or those in informal work like babysitting. Workplace exposure to adult cannabis-using peers and disposable income may be factors.

Read More on RethinkTHC

Cite This Study

RTHC-02052·https://rethinkthc.com/research/RTHC-02052

APA

Graves, Janessa M; Whitehill, Jennifer M; Miller, Mary E; Brooks-Russell, Ashley; Richardson, Susan M; Dilley, Julia A. (2019). Employment and Marijuana Use Among Washington State Adolescents Before and After Legalization of Retail Marijuana.. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 65(1), 39-45. https://doi.org/10.1016/j.jadohealth.2018.12.027

MLA

Graves, Janessa M, et al. "Employment and Marijuana Use Among Washington State Adolescents Before and After Legalization of Retail Marijuana.." The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 2019. https://doi.org/10.1016/j.jadohealth.2018.12.027

RethinkTHC

RethinkTHC Research Database. "Employment and Marijuana Use Among Washington State Adolesce..." RTHC-02052. Retrieved from https://rethinkthc.com/research/graves-2019-employment-and-marijuana-use

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.