Formal public-health statement: Cannabis (marijuana) is not harmless for teenagers
Cannabis today is often far more potent than many parents remember. For adolescents, the combination of early use, frequent use, and high-THC products is consistently linked to higher risk of serious mental-health outcomes—including psychosis and, in some people, long-lasting disorders such as schizophrenia.
Key facts parents and teens should know
- Earlier initiation and more frequent use are associated with a stronger link to psychosis and schizophrenia.1
- Using cannabis before age 18 may affect how the brain builds connections for attention, memory, and learning; some effects may be long-lasting.2
- High-potency and daily use patterns have been linked to higher odds of psychotic disorders in epidemiological studies.3
- Cannabis use disorder (problematic use) is associated with increased schizophrenia risk—particularly noted among young men in large population research.4
- Beyond mental health, established risks include dependence, impaired driving/injuries, and cognitive/psychomotor impairment.5
A formal caution (for schools, families, and community leaders)
We urge teenagers and parents to treat cannabis with the same seriousness given to other illicit drugs—especially for youth. The popular framing of cannabis as “natural” or “safe” is not a health standard, and it is not a protection against harm. For adolescents, cannabis exposure can intersect with brain development and mental-health vulnerability in ways that are unpredictable and, for some individuals, life-altering.
The risk is not uniform: not every user develops psychosis or schizophrenia. However, public-health evidence consistently shows that earlier onset, heavier use, and higher THC potency are associated with greater risk of psychotic outcomes, including long-lasting disorders in some people. This is precisely why prevention and delay of initiation are recommended as the safest approach for youth.
Bottom line: For a developing brain, “seemingly harmless” can become “permanently consequential.” If you are under 25—especially under 18—the safest choice is not to use cannabis.
What parents can do (practical steps)
- Start early, talk often: Use calm, factual language; avoid shame-based messaging.
- Ask about potency and frequency: High-THC products and daily use carry higher risk signals.
- Know your family risk: A personal/family history of psychosis is a strong reason to avoid cannabis entirely.6
- Watch for mental-health warning signs: paranoia, hallucinations, severe anxiety, sleep disruption, social withdrawal, abrupt academic decline.
- Seek help early: Early assessment is safer than waiting for symptoms to escalate.
References (public health & peer-reviewed sources)
-
CDC — Cannabis and Mental Health (psychosis/schizophrenia association stronger with earlier & heavier use).
https://www.cdc.gov/cannabis/health-effects/mental-health.html -
CDC — Cannabis and Brain Health (use before 18 may affect attention, memory, learning; some effects may be long-lasting).
https://www.cdc.gov/cannabis/health-effects/brain-health.html -
Di Forti et al., The Lancet Psychiatry (2019) — Contribution of cannabis use (including daily/high-potency patterns) to incident psychotic disorder across European sites.
https://www.thelancet.com/article/S2215-0366(19)30048-3/fulltext -
NIDA/NIH news release (May 4, 2023) — Cannabis use disorder associated with increased schizophrenia risk (population-based study).
https://nida.nih.gov/news-events/news-releases/2023/05/young-men-at-highest-risk-schizophrenia-linked-with-cannabis-use-disorder -
CAMH / Lower-Risk Cannabis Use Guidelines (professional summary) — documented risks include cognitive/psychomotor impairment, psychosis, dependence, and injuries.
https://www.camh.ca/-/media/files/lrcug_professional-pdf -
Health Canada — Lower-Risk Cannabis Use Guidelines (avoid use with personal/family history of psychosis).
https://www.canada.ca/en/health-canada/services/drugs-medication/cannabis/resources/lower-risk-cannabis-use-guidelines.html - Note: This statement is educational and not a substitute for medical advice. If a teen shows signs of psychosis (hallucinations, paranoia, severe confusion), seek urgent professional evaluation.
