Marijuana Use Among 10th Grade Students - Washington, 2014.

Some studies have suggested that long-term, regular use of marijuana starting in adolescence might impair brain development and lower intelligence quotient (1,2). Since 2012, purchase of recreational or retail marijuana has become legal for persons aged ≥21 years in the District of Columbia, Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon, and Washington, raising concern about increased marijuana access by youths. The law taxing and regulating recreational or retail marijuana was approved by Washington voters in 2012 and the first retail licenses were issued in July 2014; medical marijuana use has been legal since 1998. To examine the prevalence, characteristics, and behaviors of current marijuana users among 10th grade students, the Washington State Department of Health analyzed data from the state's 2014 Healthy Youth Survey (HYS) regarding current marijuana use. In 2014, 18.1% of 10th grade students (usually aged 15-16 years) reported using marijuana during the preceding 30 days; of these students, 32% reported using it on ≥10 days. Among the marijuana users, 65% reported obtaining marijuana through their peer networks, which included friends, older siblings, or at a party. Identification of comprehensive and sustainable public health interventions are needed to prevent and reduce youth marijuana use. Establishment of state and jurisdiction surveillance of youth marijuana use could be useful to anticipate and monitor the effects of legalization and track trends in use before states consider legalizing recreational or retail marijuana.