Prevention-based interventions are effective in increasing cannabis risk perception and reducing cannabis use among adolescents.
Increased knowledge and a greater perception of cannabis risk in adolescents are associated with decreased current usage and reduced intentions for future use, according to study results published in the Journal of Adolescent Health. While prevention-based interventions were generally effective in enhancing knowledge and perception of cannabis risk, legislative changes demonstrate considerable heterogeneity in outcomes.
Cannabis remains the predominantly used illicit substance by adolescents on a global scale, and given recent legislative changes to cannabis legalization, investigators aimed to establish a comprehensive understanding of adolescents’ general knowledge and perception of risk for cannabis and whether legislation impacted these variables.
The investigators conducted a systematic literature review by searching publication databases from inception to February 2022 for articles that reported on cannabis knowledge and its risk perception among children and adolescents (10 to 18 years of age). Levels of evidence for each study included were determined using the Center for Evidence Based Medicine’s framework, with Level 1A (systematic review of randomized controlled trials) representing the highest level of evidence and Level 5 (expert opinion, physiology bench research, or “first principles”) being the lowest.
A total of 133 articles were included in the final analysis. Most studies (n=93) were categorized as evidence grade level 2C, involving outcome studies from large database registries and population-based data, while 22% (n=30) met the criteria for level 2B studies, which includes cohort studies and lower-quality RCTs. Over 90% of the studies were conducted in high-income countries (eg, United States, Canada, Australia, England, France), with limited representation from upper and lower middle-income countries.
Overall, increased awareness and knowledge regarding the perceived risk for cannabis among adolescents was frequently associated with reduced current usage and future use intentions of cannabis. Studies investigating associations over time demonstrated a rise in adolescent cannabis use alongside a decline in risk perception. However, the investigators observed that prevention interventions frequently improved knowledge and risk perception among these adolescents. For example, a Psychostimulant and Cannabis Module led to significantly higher levels of cannabis-related knowledge in intervention groups compared with controls, even at 10 months post-intervention (P <.001). Additionally, a life-skills training program with a drug education unit for middle school students resulted in reduced lifetime (P =.05) and recent (P <.03) marijuana use 2 years after intervention, relative to controls.
In contrast, legislative changes led to heterogeneous knowledge and risk perception outcomes. Medicinal marijuana legislation consistently demonstrated a reduction in risk perception among adolescents, while studies that evaluated recreational marijuana legislation observed significant variability in both knowledge and use outcomes.
Notably, studies that assessed adolescents’ knowledge and perception of risks associated with cannabis use as a primary outcome revealed that a lack of comprehensive understanding regarding the health implications of marijuana usage was consistently associated with higher rates of current usage and intentions for future use.
Review authors concluded, “[T]argeted public health strategies that seek to increase cannabis-related knowledge among youth and disseminate information about the potential health harms of cannabis use should continue and be prioritized as a means of protecting youth and mitigating rates of cannabis use in adolescents.”
The findings of this review may be limited by the inclusion of manuscripts exclusively published in English, and the high risk for bias found in 95% of included studies.
This article originally appeared on Psychiatry Advisor