Teen Marijuana Use

Teen marijuana use in King County has declined in recent years.

The safety of marijuana is not well established, and there are potential health risks and harms associated with its use, which is illegal for those under the age of 21. Research shows that marijuana use can have long-term effects on the developing brain when use begins in adolescence, especially with regular or heavy use. 

In 2018 and 2021, an average of 11.8% of King County teens in grades 8, 10 and 12 had used marijuana in the last 30 days.  

• Trends: The percentage of teens in King County who used marijuana rose from 2004 to 2012 and has been declining since then. While not definitively related, the decline follows a policy change in 2012 which legalized recreational marijuana use for adults age 21 and older in Washington, and the COVID-19 pandemic starting in 2020. While current marijuana use among teens in 2021 (8.4%) was the lowest rate ever measured in King County, this issue should be monitored closely as teens have experienced many changes due to the COVID-19 pandemic and associated mitigation strategies.      

• Race and ethnicity: Multiple race (15.3%) teens had higher rates of current marijuana use than the King County average. Asian teens (4.9%) were less likely than the county average to use marijuana, although disaggregated data shows some differences in teen marijuana use by Asian ethnic group. Teens identifying as Chinese, Indian, Korean or Vietnamese had marijuana use rates lower than the county average. However, teens identifying as Cambodian/Khmer (9.2%), Filipino (11.1%) or Japanese (11.2%) had marijuana use rates similar to the county average.  

• Grade level: Marijuana use increased with grade level, from 3.7% among 8th graders up to 20.0% among 12th graders.     

• Sexual orientation: Teens who identified as lesbian, gay or bisexual had higher rates of marijuana use (16.4%) than the King County average.    

• Gender: Transgender teens (16.5%) had higher rates of marijuana use than the King County average.

• Region: Teens in Seattle (16.7%) were more likely to have used marijuana than the county average. Teens in East Region (9.0%) were less likely to be current users.   

• Additional data is available here on teen alcohol and illegal drug use.   

Resources:

Youth Marijuana Prevention Program

King County Health and Human Services priorities regarding marijuana legalization

Health Effects of Marijuana (Centers for Disease Control and Prevention)