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Study breakdown

Cannabis use declined among King County students from 2008-2021, but girls overtook boys in use rates for the first time

ObservationalModerate evidence
The takeaway

Among students in grades 8, 10, and 12 in King County, Washington, cannabis use declined from 2008 to 2021, but a historic shift occurred: by 2021, female students had higher current use prevalence than male students for the first time.

School-based prevention program designers; public health officials tracking youth substance use trends in legalized states.

Girls surpassed boys in cannabis use for the first time in 2021

What the researchers found

During 2008-2021, cannabis use declined among both sexes. In 2008, male students had 4.8% higher prevalence than female students. By 2014-2016, rates were statistically equal. In 2021, current use was 1.3% higher among female students than male students for the first time. Frequent use (6+ days/month) remained similar between sexes. 12th graders had the highest use rates.

Why it matters

The reversal of the sex gap in cannabis use is a meaningful public health signal. If female students are now more likely to use cannabis than male students, prevention programs designed primarily for boys may be missing the current reality.

The numbers in context

Range: 33,439-39,391 students per cycle. 2008 sex gap: males 4.8% higher. 2021 gap: females 1.3% higher. Frequent use similar between sexes. 12th graders highest, followed by 10th, then 8th.

How the study worked

Analysis of the Healthy Youth Survey administered by Washington State Department of Health, restricted to King County students in grades 8, 10, and 12 across seven survey periods (2008-2021). 33,439-39,391 students per cycle. Weighted generalized linear regression with sex-by-year interaction.

What this study cannot tell us

Single county in Washington state; may not generalize to other regions. Self-reported use in school settings may undercount. Students absent from school or who dropped out are missed. 2021 data collected during COVID-19 may reflect unusual patterns.

How to read the evidence

Large repeated cross-sectional survey with over 33,000 students per cycle. Strong trend data but single-county scope.

When this study was published

2024 study

The bigger picture

This sex-based crossover in cannabis use mirrors similar trends seen with alcohol and may reflect broader shifts in gendered norms around substance use. Prevention strategies may need updating to reflect these changing demographics.

Questions still open

  • Is the sex crossover unique to King County or a national trend? What factors are driving increased female relative to male cannabis use?

Common questions

Did legalization increase youth cannabis use in Washington?
No. Overall use declined from 2008 to 2021, spanning both the pre- and post-legalization periods. The notable change was the shift in sex-based patterns, not overall prevalence.
Why might girls be using more cannabis now?
The study did not investigate reasons. Possible factors include changing social norms, different risk perceptions by sex, marketing influences, or shifts in how cannabis is used (e.g., edibles vs smoking).

Read the original research

Cannabis Use Among Students in Grades 8, 10, and 12, by Sex - King County, Washington, 2008-2021.

MMWR. Morbidity and mortality weekly report, 73(2), 27-31

Citation

Esie, Precious; Ta, Myduc. (2024). Cannabis Use Among Students in Grades 8, 10, and 12, by Sex - King County, Washington, 2008-2021.. MMWR. Morbidity and mortality weekly report, 73(2), 27-31. https://doi.org/10.15585/mmwr.mm7302a1

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