Cannabis use among U.S. adolescents in the era of marijuana legalization: a review of changing use patterns, comorbidity, and health correlates

Abstract

Decriminalization, medicalization, and legalization of cannabis use by a majority of U.S. states over the past 25 years have dramatically shifted societal perceptions and use patterns among Americans. How marijuana policy changes have affected population-wide health of U.S. youth and what the downstream public health implications of marijuana legalization are topics of significant debate. Cannabis remains the most commonly used federally illicit psychoactive drug by U.S. adolescents and is the main drug for which U.S. youth present for substance use treatment. Converging evidence indicates that adolescent-onset cannabis exposure is associated with short- and possibly long-term impairments in cognition, worse academic/vocational outcomes, and increased prevalence of psychotic, mood, and addictive disorders. Odds of negative developmental outcomes are increased in youth with early-onset, persistent, high frequency, and high-potency Δ-9-THC cannabis use, suggesting dose-dependent relationships. Cannabis use disorders are treatable conditions with clear childhood antecedents that respond to targeted prevention and early intervention strategies. This review indicates that marijuana policy changes have had mixed effects on U.S. adolescent health including potential benefits from decriminalization and negative health outcomes evidenced by increases in cannabis-related motor vehicle accidents, emergency department visits, and hospitalizations. Federal and state legislatures should apply a public health framework and consider the possible downstream effects of marijuana policy change on paediatric health.

Keywords:

• Adolescents
• cannabis
• marijuana
• legalization
• psychiatric comorbidity
• health correlates

Disclosure statement

Dr. Hammond receives grant support from the National Institute on Drug Abuse/American Academy of Child & Adolescent Psychiatry (NIDA/AACAP) career development award (K12DA000357) and serves as a scientific advisor for the National Courts and Science Institute. Dr. Sharma receives grant support from an AACAP Pilot Research Award for Junior Faculty. Drs. Chaney and Hendrickson report no conflicts or financial disclosures.

Additional information

Funding

Support for this study came from a National Institute on Drug Abuse/American Academy of Child & Adolescent Psychiatry (NIDA/AACAP) Physician Scholar in Substance Abuse Research grant K12DA000357 (Hammond) and an AACAP Pilot Research Award for Junior Faculty (Sharma).