Cannabis, Prescription Drug Use Disorder More Commonly Begins in Adolescence than Young Adulthood

Substance use disorder is more prevalent among cannabis and prescription drug users who initiated use in their adolescence than in their early adulthood, according to findings from a nationally-representative study.

A new research letter from investigators at the National Institution on Drug Abuse (NIDA) at the National Institutes of Health (NIH) underscores a gap in age-based substance abuse screening in the US, while also contributing to the understanding of how younger age is closely associated with developed dependency on certain substances.

Led by Beth Han, MD, PhD, MPH, of NIDA, the investigators sought to observe the prevalence of specific substance use disorders since first drug use or prescription misuse in adolescents and young adults.

For the matter of their assessment, drug use included tobacco, alcohol, cannabis, cocaine, methamphetamine and heroin, and prescription misuse included opioids, stimulants and tranquilizers. Adolescents ranged from 12-17 years old, and young adults ranged from 18-25 years old.

As they noted, previous research suggests earlier age at drug initiation is linked to a faster progression toward substance abuse disorder.

“However, prevalence of specific SUDs as a function of time since first substance use among young people has not, to our knowledge, been investigated,” they wrote.

Han and colleagues conducted their assessment with data from the 2015-2018 National Surveys on Drug Use and Health (NSDUH), of the Substance Abuse and Mental Health Services Administration. The NSDUH provides nationally-representative collected data on substance use based on lifetime use, use in the last 12 months, initiation dates, and substance use disorder prevalence.

From their analysis of data from survey participants aged 12-25 years old in the observed time frame, alcohol, cannabis, and tobacco were the most frequently reported substances. Lifetime substance use was 26.3% (95% CI, 25.4 – 27.2) for alcohol, 15.4% (95% CI, 14.7 – 16.1) for cannabis, and 13.4% (95% CI, 12.7 – 14.1) for tobacco among adolescents in 2018. For the same year among young adults, rates were 79.7%, 51.5%, and 55%, respectively.

The investigators observed differences in substance, age group, and time since initiation among participants with substance use disorder.

Adjusted cannabis use disorder prevalence was greater among adolescents versus young adults within 12 months of initiation (10.7% vs 6.4%), as well as ≥36 months (20.1% vs 10.9%).

The prevalence of lifetime cocaine, methamphetamine, and heroin use among young adults was 11.4%, 2.5%, and 1.3%, respectively, in 2018. Within 12 months of initiation, adjusted prevalence was greater for methamphetamine user disorder (24.8%) and heroin use disorder (30.9%) than for cocaine use disorder (5.6%). Estimated rates for adolescents were not reported due to limited sample counts.

The prevalence of lifetime prescription drug misuse was 9.2% among adolescents and 26.3% among young adults in 2014. Adolescents reported consistently greater prescription opioid, stimulant, and tranquilizer use disorders than adults, when stratified by lifetime misuse.

As Han colleagues noted, there is currently discrepancies in substance use screening guidance. The American Academy of Pediatrics currently recommends screening among adolescents, while the US Preventive Services Task Force recommends primary care-setting screenings among adults only.

“Our results underscore the vulnerability of adolescents to substance use disorders and the importance of screening for substance misuse among adolescents,” they wrote.

What’s more, the significant rate of opioid overdose deaths and increasing methamphetamine deaths in the US put an urgency on the push for prevention, screening, and treatment of substance use disorder among young adults as well.

They called for future research evaluating the efficacy of substance use and use disorder screening in primary care settings, as well as the proceeding treatment thereof.

The research letter, “Prevalence of Substance Use Disorders by Time Since First Substance Use Among Young People in the US,” was published online in JAMA Pediatrics.