The increasing use of cannabis and vaping among U.S. adolescents may be associated with how teens spend their time, according to a study published in Substance Use & Misuse.

Specifically, several factors, such as social engagement, participation in structured activities, level of adult supervision and paid employment, correlated with substance use overall.

Using data from 536,291 adolescents in the Monitoring the Future Study gathered through annual, nationally-representative surveys from 1991 to 2019, Noah T. Kreski, MPH, data analyst for Columbia University Mailman School of Public Health, and colleagues analyzed trends in use of cigarettes, alcohol, cannabis, other substances and vaping of nicotine for those in grades eight, 10 and 12. They then categorized respondents into six groups based on amounts of social time, level of engagement in organized activities, paid employment and, for those with high social time and high engagement, whether activities were more supervised, such as sports, or less supervised, such as dating or parties.

Noah T. Kreski

“We had seen such strong patterning of internalizing symptoms (like depressive symptoms and low self-esteem) based on how young people spend their time [in our previous research]. Extending that work to substance use seemed like a natural next step,” Kreski told Healio.

Substance use tied to time use patterns

Study results revealed declines across decades for most substance use outcomes, including alcohol, cigarette and other substance use, with the largest decreases noted among groups with significant paid employment or high levels of social time, either with low engagement in other activities or lower levels of supervision. Notably, initial prevalence of substance use was highest in these groups. Conversely, the smallest decreases were observed among groups with low levels of peer socialization, although these groups had very low prevalence of substance use in general, according to the researchers.

Despite decreases in substance use over time, cannabis use increased, with the smallest increase seen in the group with low levels of social time and low engagement in organized activities and the largest increase seen in the paid employment group.

Vaping, for which data were available from 2017 onward, also substantially increased during the study period. The largest increase in nicotine vaping occurred among adolescents in the highly social and engaged group with less supervision. In contrast, the largest increase in cannabis vaping occurred among those who were highly social but disengaged. Vaping of both substances was most prevalent in the highly social and engaged group with less supervision.

Substance use overall was lowest in the groups with low levels of social time and highest in the highly social and employed groups, according to the data.

“While some of the results aligned with expectations (like low supervision or high time with peers contributing to higher substance use), it was surprising to see that working a paid job was a risk factor for substance use as well. While the pathways are unclear, future research should look at this group more and provide support where needed,” Kreski said.

In terms of specific substance use, data also showed the following:

• 15% of respondents reported any past 2-week binge drinking.
• 27.4% reported drinking alcohol in the past month.
• 14.7% reported smoking cigarettes in the past month.
• 12.6% reported any past-month cannabis use.
• 8.6% reported past-month use of other substances.
• 12.3% reported nicotine vaping.
• 6.2% reported cannabis vaping.

Importantly, these data perhaps indicate the need for greater public health measures, particularly those targeting vaping and cannabis use, the researchers noted.

“With how universal the rising trends are, parents should check in with their adolescents about substance use — not from a place of judgment or punishment but open discussion and support. Empowering all young people to make the best, informed choices they can while focusing interventions on cannabis and vaping is a great next step,” Kreski said.

Looking ahead

In the future, Kreski and colleagues are planning to evaluate how these time use patterns relate to externalizing symptoms, such as theft or fighting, but other areas, especially those that interest adolescents themselves, warrant further study.

“Apart from that, I’d love to encourage the development of a system where young people can directly provide feedback on the topics and problems that they find most important, what they think should be studied further. Research should always be guided by the population being studied, and empowering young people is incredibly important,” Kreski said.