Prevalence of Substance Use Disorders by Time Since First Substance Use Among Young People in the US

Earlier age at drug initiation has been shown to be associated with faster transition to substance use disorder (SUD).¹ However, prevalence of specific SUDs as a function of time since first substance use among young people has not, to our knowledge, been investigated. We examined the prevalence of specific SUDs since first drug use (including tobacco, alcohol, cannabis, cocaine, methamphetamine, and heroin) or prescription misuse (including opioids, stimulants, and tranquilizers) in adolescents aged 12 to 17 years and young adults aged 18 to 25 years.

Data were from participants aged 12 to 25 years in the 2015 to 2018 National Surveys on Drug Use and Health (NSDUH) of the Substance Abuse and Mental Health Services Administration,^1,2 excluding prescription drug data from 2005 to 2014 because not all initiation dates were collected in 2015 to 2018. Data were analyzed in July 2020. The NSDUH collects nationally representative data on substance use according to lifetime use, use in the past 12 months, and initiation date as well as SUDs (using Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition] criteria) among noninstitutionalized civilian populations. This research was approved by the institutional review board at RTI International. Due to the sensitive contents of the NSDUH, the US Office of Management and Budget and the IRB at RTI International only require verbal informed consent. For respondents aged 12 to 17 years, verbal consent was received from each participant and their parent or legal guardian, or participants alone for those aged 17 years and living independently (eg, in a dormitory). Multivariable logistic regressions were conducted using SUDAAN version 11.0.1 (RTI International) to account for complex sample design and sampling weights. Two-tailed t tests were conducted, and significance was set at P < .05.

Alcohol, cannabis, and tobacco were the most commonly used substances. The prevalence of lifetime substance use among adolescents in 2018 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 young adults in 2018, prevalence of lifetime substance use was 79.7% (95% CI, 78.9-80.5) for alcohol, 51.5% (95% CI, 50.4-52.6) for cannabis, and 55.0% (95% CI, 53.9-56.1) for tobacco. Prevalence of SUDs differed by substance, age group, and time since initiation. Adjusted prevalence of cannabis use disorder was higher among adolescents than among young adults within 12 months of initiation (10.7%; 95% CI, 9.3-12.3 vs. 6.4%; 95% CI, 5.2-7.9) and at more than 36 months (20.1% [95% CI, 18.0-22.3] vs. 10.9% [95% CI, 10.3-11.4]) (Table). Prevalence of alcohol use disorder and nicotine dependence did not differ between the 2 groups within 12 months of initiation but was higher for young adults in subsequent periods.

Among young adults, prevalence of lifetime cocaine, methamphetamine, and heroin use in 2018 was 11.4% (95% CI, 10.7-12.1), 2.5% (95% CI, 2.2-2.8), and 1.3% (95% CI, 1.1-1.5), respectively. Within 12 months of initiation, adjusted prevalence was higher for methamphetamine use disorder (24.8% [95% CI, 16.8-34.9]) and heroin use disorder (30.9% [95% CI, 20.6-43.4]) than for cocaine use disorder (5.6% [95% CI, 4.2-7.4]). Estimates for adolescents were not reported owing to limited samples.

Prevalence of lifetime misuse of prescription drugs in 2014 was 9.2% (95% CI, 8.7-9.7) among adolescents and 26.3% (95% CI, 25.4-27.2) among young adults. Among the population with lifetime misuse, adjusted prevalence of prescription opioid use disorder, prescription stimulant use disorder, and prescription tranquilizer use disorder were consistently higher for adolescents than for young adults (Figure). Prevalence since time of initiation for adolescents was stable for prescription opioid use disorder and decreased for prescription stimulant use disorder and prescription tranquilizer use disorder, whereas for young adults, prevalence increased for prescription opioid use disorder and was stable for prescription stimulant use disorder and prescription tranquilizer use disorder.

Using nationally representative data, we observed higher prevalence of SUD within 12 months of cannabis and prescription misuse initiation among adolescents than among young adults (eg, cannabis use disorder: 10.7% vs 6.4% within 12 months; 20.1% vs 10.9% at more than 36 months), consistent with the association of faster transition to SUDs with younger age at drug initiation. Although the American Academy of Pediatrics recommends screening for substance use among adolescents,³ the US Preventive Services Task Force recommends such screening in primary care settings only among adults.⁴ Our results underscore the vulnerability of adolescents to SUDs and the importance of screening for substance misuse among adolescents.

For young adults with lifetime use, prevalence within 12 months of drug initiation was high for heroin use disorder (30.9%) and methamphetamine use disorder (24.8%). Considering the high rates of opioid fatalities and rising numbers of methamphetamine deaths,⁵ these results highlight the urgency of prevention, screening, and treatment of SUDs in this age group.

This study has limitations. Prevalence of SUDs may have been underestimated because NSDUH excludes incarcerated individuals and homeless individuals not living in shelters and is subject to recall and social biases. Nevertheless, our results identified adolescents as highly vulnerable to SUDs, supporting the need for research to evaluate the efficacy of screening for substance use and SUDs in primary care settings and the timely treatment thereof.

Accepted for Publication: November 29, 2020.

Published Online: March 29, 2021. doi:10.1001/jamapediatrics.2020.6981

Corresponding Author: Beth Han, MD, PhD, MPH, National Institute on Drug Abuse, National Institutes of Health, 301 N Stonestreet Ave, 3WFN Room 09C24, MSC 6024, Bethesda, MD 20892-6024 (beth.han@nih.gov).

Author Contributions: Dr Han had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Drs Volkow and Han shared senior authorship equally.

Concept and design: All authors.

Acquisition, analysis, or interpretation of data: Volkow, Han, Compton.

Drafting of the manuscript: Volkow, Han.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Han.

Administrative, technical, or material support: Volkow, Han.

Supervision: Volkow, Einstein.

Conflict of Interest Disclosures: Dr Compton reports stock ownership in General Electric Co, 3M Co, and Pfizer Inc. No other disclosures were reported.

Disclaimer: The findings and conclusions of this study are those of the authors and do not necessarily reflect the views of the National Institute on Drug Abuse of the National Institutes of Health and the US Department of Health and Human Services.