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Researchers at the University of California San Diego examined data from 11,880 participants in the Adolescent Brain Cognitive Development Study, a national project that has tracked children since ages 9 and 10.
UC San Diego serves as the national coordinating center for the study. Using annual and mid-year assessments collected between 2016 and early 2024, the team found that substance use increased steadily with age, reaching 38% of participants reporting lifetime use of at least one substance by age 16.
Researchers noted that teens reported alcohol, cannabis and nicotine as the substances most commonly used. Other substance useage remained far less common by comparison.
Girls Overtake Boys After Age 13
One notable pattern that emerged involves how substance use differs by sex over time. Boys reported higher rates of use before age 12.
But starting around age 13, that pattern reverses, and girls report higher rates of alcohol, cannabis and nicotine use than boys, with the gap widest for nicotine.
At age 14, for example, 11.3% of girls reported nicotine use compared with 8% of boys. Cannabis use was reported by 8.8% of girls versus 7% of boys, and alcohol use by 8.3% of girls versus 6.5% of boys.
The pattern extended to polysubstance use, defined as using two or more substances. Nearly 15% of participants reported polysubstance use at some point in the study, most commonly a combination of nicotine and cannabis. Girls also reported higher rates of polysubstance use after age 13, particularly combinations involving nicotine.
What This Means for Treatment Seekers
For parents and caregivers, these findings remind them that conversations about substance use, and any warning signs, are worth having earlier than the high school years.
Researchers noted that prevalence estimates adjusted for national demographics closely matched the study’s raw results, suggesting these numbers reflect broader patterns among American adolescents rather than a quirk of the study sample.
For families who notice early signs of nicotine, cannabis or alcohol use in a young teen, options exist specifically designed for adolescents.
Treatment for this age group typically differs from adult care by incorporating family involvement, school coordination and age-appropriate behavioral therapies.
Why Early Patterns Matter Long Term
The study’s lead author, Ryan Sullivan, PhD, a postdoctoral research fellow at the UC San Diego School of Medicine, published the findings on July 23, 2026 in Drug and Alcohol Dependence Reports.
The research team says the updated estimates give scientists an important benchmark for understanding how substance use emerges during adolescence and how early use may relate to brain development, mental health and long-term health outcomes.
Nicotine and cannabis combinations were the most frequently reported polysubstance pattern, a detail that may be useful for parents and clinicians trying to identify risk before it escalates.
Co-occurring use of multiple substances during adolescence has been associated in prior research with a higher likelihood of developing more serious substance use patterns later, which is part of why researchers continue to track these trends closely over time.
Exploring Treatment Options
Families concerned about a teen’s substance use do not need to wait for a crisis to seek guidance. Age-appropriate treatment programs address not just the substance use itself but also the family dynamics, academic pressures and peer relationships that often accompany it.
Understanding the differences between adolescent and adult treatment programs, along with what a first conversation with a provider might look like, can make the process feel less overwhelming for both teens and parents.
Rehab.com’s directory includes treatment centers that specialize in adolescent care, along with resources for understanding insurance coverage and evidence-based therapies for young people. Call to speak with a treatment advisor about age-appropriate care.
