They view it as less harmful than alcohol, nicotine vapes or cigarettes. For families and clinicians navigating adolescent substance use, the findings carry direct implications for early intervention and mental health treatment.
What the Research Found
Researchers at UC San Diego’s Herbert Wertheim School of Public Health analyzed survey responses from more than 175,000 California students, drawing on two large statewide school surveys conducted in 2019–2020 and 2024.
Led by professor Shu-Hong Zhu, PhD, the study examined how adolescents perceive the risk of both regular and occasional use of cannabis compared to alcohol, nicotine vapes and cigarettes.
The pattern was consistent across both survey periods: cannabis ranked as the substance teens found least worrying. In the earlier survey, roughly two-thirds of students considered regular cannabis use harmful.
A notably lower share than those who viewed alcohol, vaping or cigarettes as harmful. The findings were published May 5, 2026, in the journal Drug and Alcohol Dependence.
How Age and Peer Influence Shape Teen Perceptions
The study’s findings on age trends are particularly striking for addiction treatment professionals. While perceived harm of alcohol and tobacco products generally held steady or increased as students moved through higher grade levels, perceptions of cannabis risk moved in the opposite direction, declining significantly by 12th grade.
Personal experience also played a role. Teens who had used cannabis were less likely to view it as harmful, and that perception gap was larger for cannabis than for any other substance studied.
Peer environment compounded the effect: adolescents with more friends who used cannabis rated it as less risky, again with the strongest influence seen for cannabis specifically.
Why Researchers Are Concerned
Despite an overall decline in adolescent cannabis use in recent years, study authors warn that reduced risk perception remains a serious public health concern.
Researchers note that cannabis use during adolescence carries real risks to brain development, cognitive function and mental health. These risks may be obscured by shifting social norms and widespread pro-cannabis messaging in states where adult use is legal.
The authors specifically call for prevention and education programs that more directly address cannabis-specific risks, rather than relying on general substance use messaging that may treat all substances equally.
What This Means for Addiction Treatment
When adolescents underestimate the risks of cannabis, they are less likely to seek help or accept it when offered. For treatment providers, this perception gap signals a need for screening tools and intake conversations that specifically address cannabis use alongside other substances.
Early addiction treatment intervention, including individual counseling, family therapy and co-occurring mental health support, is especially important given evidence linking adolescent cannabis use to developmental and psychiatric outcomes.
What This Means for Treatment Seekers
Parents and caregivers researching addiction treatment options should be aware that cannabis may not feel dangerous to their teen, even if use has escalated or is affecting school, mood or relationships.
Programs offering adolescent-specific addiction treatment typically include specialized assessments that go beyond surface-level use patterns to evaluate mental health and developmental impact.
Understanding insurance coverage for rehab that includes adolescent behavioral health services can reduce barriers to getting help early.
Exploring Treatment Options
If you’re concerned about a teen’s cannabis use or other substance use, early evaluation at a qualified rehab center can make a significant difference in long-term outcomes. Key steps include:
- Comparing rehab centers with adolescent-specific addiction treatment programs
- Verifying that facilities address co-occurring mental health conditions alongside substance use
- Understanding insurance coverage for rehab, including mental and behavioral health benefits under the ACA
- Asking about evidence-based therapies such as cognitive behavioral therapy (CBT) and motivational interviewing
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