Existing evidence suggests cannabis use during adolescence is associated with brain changes in structure, function, and connectivity that may persist into adulthood.
Parents, educators, clinicians, and policymakers interested in adolescent cannabis risks
Adolescent cannabis users showed largely increased functional brain activation compared to controls
What the researchers found
Adolescent cannabis users show altered functional connectivity within established brain circuits, with largely increased functional activation compared to controls. The endocannabinoid system undergoes developmental changes during adolescence that may make it more susceptible to cannabis exposure.
Why it matters
Adolescence involves critical brain development, and understanding whether cannabis use during this window carries elevated risk compared to adult use has direct public health implications.
The numbers in context
No specific effect sizes reported; the review synthesizes findings across multiple studies.
How the study worked
Narrative review synthesizing human neuroimaging studies of adolescent cannabis users, cognitive performance data, and preclinical evidence on adolescent-specific vulnerability.
What this study cannot tell us
Narrative review (not systematic); many underlying studies are cross-sectional, making it difficult to establish whether cannabis caused observed brain changes or whether pre-existing differences preceded use.
How to read the evidence
Narrative review synthesizing multiple studies, though many underlying studies have cross-sectional designs.
When this study was published
Published in 2020.
The bigger picture
As cannabis legalization expands, understanding age-specific risks is essential for evidence-based policy and clinical guidance about adolescent cannabis use.
Questions still open
- How permanent are cannabis-associated brain changes after adolescents stop using? What heritable risk factors might increase individual vulnerability?
Common questions
Does this review prove cannabis is more harmful to teenagers than adults?
Do the brain changes reverse if an adolescent stops using cannabis?
Read the original research
Is the Adolescent Brain at Greater Vulnerability to the Effects of Cannabis? A Narrative Review of the Evidence.
Frontiers in psychiatry, 11, 859
Citation
Blest-Hopley, Grace; Colizzi, Marco; Giampietro, Vincent; Bhattacharyya, Sagnik. (2020). Is the Adolescent Brain at Greater Vulnerability to the Effects of Cannabis? A Narrative Review of the Evidence.. Frontiers in psychiatry, 11, 859. https://doi.org/10.3389/fpsyt.2020.00859
Explore the wider topic
- How to Talk to Your Teenager About Weed (Without Losing Them)
- My Kid's Friends Smoke Weed: A Parent's Guide
- I Smoke Weed But Don't Want My Kids To: Navigating the Hypocrisy
- Quitting Weed as a Parent: Why It Is the Hardest and Most Important Quit
- Quitting Weed as a Teen or Young Adult
- My Kid Is Smoking Weed: A Parent's Guide