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

The Lower-Risk Cannabis Use Guidelines’ (LRCUG) recommendations: How are Canadian cannabis users complying?

“…Available indicators from the surveys suggest that adult Canadians, on average, initiate cannabis use around age 19 years. This age makes them eligible for legal cannabis use and procurement (in most provinces) under legalization, and thereby should help to reduce risks for key cannabis-related health and social harms as particularly evidenced for young people ( D’Amico et al, 2017 , Hammond et al, 2020a , Macleod et al, 2004 ). However, the initiation ages reported are partly artefactual since the surveys’ sampling frames are limited mainly to adult samples and, overall, sizeable proportions of Canadians are reported to initiate cannabis use at ages below 18 years.…”

A review investigating the relationship between cannabis use and adolescent cognitive functioning

“…Cannabis, also referred to as marijuana, is one of the most commonly used substances globally in terms of occurrence (the likelihood of an individual becoming a user) and frequency (number of users in the population) [ 1 ]. In terms of care and treatment, cannabis is the most commonly reported illicit psychoactive substance used among U.S. youth [ 2 , 3 • ]. Throughout the past 25 years, although its decriminalization, medicalization, and legalization in the U.S. has led to a shift in societal perceptions and usage patterns among Americans, there is no consensus that state-level cannabis laws and medical marijuana laws (MML) moving towards decriminalization and legalization have necessarily increased cannabis use among adolescents [ 3 • ].…”

“…In terms of care and treatment, cannabis is the most commonly reported illicit psychoactive substance used among U.S. youth [ 2 , 3 • ]. Throughout the past 25 years, although its decriminalization, medicalization, and legalization in the U.S. has led to a shift in societal perceptions and usage patterns among Americans, there is no consensus that state-level cannabis laws and medical marijuana laws (MML) moving towards decriminalization and legalization have necessarily increased cannabis use among adolescents [ 3 • ]. The statistics reflect that across the United States, there was no increase in average frequency of cannabis use among adolescents post-legalization in the US, with some data demonstrating an average 7% decrease in monthly use among adolescents post cannabis legalization (K. Winters, PhD, unpublished data, 2019).…”

“…During this time, there was an increase in cannabis consumption among middle and high school students. The perception of cannabis harmfulness subsequently increased in the 80’s to early 90’s, and by the mid 90’s, the perception of cannabis harmfulness began to decrease again [ 3 • ]. A 2019 study found risk perception in adolescents was directly associated with lifetime cannabis use [ 8 ].…”

“…Evidence in the extant literature regarding the long-term effects of chronic cannabis use on adolescent neurological functioning is limited and inconclusive. Researchers believe there is some evidence suggesting structural changes may result from persistent use, and these changes might be correlated with decreased academic performance, impairments in cognition, and increased prevalence of addictive and mood disorders [ 3 • , 10 ].…”