Overall substance use decreases in adolescents, while cannabis and vaping increases

Substance use has remained high in adolescents despite declines, while cannabis use and vaping have risen, according to a recent study.

Substance use has been associated with physical and mental health consequences, such as sleep disturbances, academic problems, injuries, psychological issues, and substance use disorders. Overall, substance use has been declining among adolescents, with the exceptions of cannabis and vaping.

The decline in substance use can be partly attributed to the reduction of known risk factors, such as unsupervised time with friends, dating, and partying. As cannabis use and vaping remain high, investigators believe that an understanding of trends could help explain why certain forms of substance use declined while others remained high.

In contrast with the decrease in alcohol and other substance use, cannabis has seen a steady increase in recent years, with a bigger spike in use seen in vaping. As of 2019, over 1 in 5 adolescents in grade 10 vape nicotine, along with 1 in 4 adolescents in grade 12. This has led to concerns of adverse health effects such as lung injury associated with nicotine use.

Investigators conducted a study to estimate the association between patterns of adolescent time use and types of substance use. The study also tested trends in substance use and relations between time use groups and substance use groups, along with relations between time use patterns and cannabis and vaping use.

Data was gathered from Monitoring the Future on 536,291 adolescents, grades 8, 10, and 12. A multi-stage random sampling design was used to select schools, which were offered to participate in the study for 2 years. In the schools which accepted, students were given self-administered questionnaires.

Adolescent time use was organized into various domains, such as social, academic, and recreational. Latent Profile Analysis was used to form patterns from adolescent time use. Social time and engagement in organized activities were used to define time use groups, which were then divided based on level of time unsupervised.

Substance use was divided into 7 categories: past-month cigarette smoking, alcohol use, cannabis use, other substance use, nicotine vaping, cannabis vaping, and past two-week drinking.

Two-week binge drinking was reported by 15% of participants, alcohol use by 27.4%, cigarette use by 14.7%, any past-month cannabis use by 12.6%, other substance use by 8.6%, nicotine vaping by 12.3%, and cannabis vaping by 6.2%.

In most types of substance uses, rates had declined over the examined period. Substance use decrease was often defined by significant paid employment or high levels of social time. Groups with low levels of social time had the lowest decrease in substance use.

Cannabis use increased across all groups, highest for the workers group and lowest for the low social group. In comparison, vaping saw the greatest increase in groups with high social engagement and low supervision.

These results indicate that social time with peers increases risk of substance use, but that trends have been declining overall. As cannabis use and vaping are the exceptions, investigators urged further investigations into use of these products among adolescents, especially in unsupervised social settings.

Reference

Kreski N, Cerda M, Chen Q, Hasin DS, Martins SS, Mauro PM, et al. Adolescents’ use of free time and associations with substance use from 1991 to 2019. Substance Use and Misuse. 2022. doi:10.1080/10826084.2022.2115849