Regular cannabis use during teenage years is associated with slower development of memory and attention skills, according to research reported by The Independent, raising fresh concerns about the impact of the drug on the still-forming adolescent brain.
Scientists point out that the human brain reaches only around 80% of its full development during adolescence, with critical processes related to cognition, impulse control, and decision-making continuing well into a person's mid-20s. This window of ongoing development, researchers say, may make young users particularly susceptible to the effects of cannabis.
What the research found
The findings suggest that teenagers who use cannabis show reduced gains in two key cognitive areas - memory and focus - compared with peers who do not use the drug. These are functions that typically improve significantly during adolescent years as the brain matures.
Rather than indicating an immediate loss of ability, the concern centers on a slowing of normal cognitive development. Researchers describe this as a failure to gain ground during a critical period, which could have longer-term consequences for academic performance and overall brain health.
Why adolescence matters
The adolescent brain undergoes substantial structural and functional changes, including the pruning of neural connections and the strengthening of pathways involved in reasoning and memory. Experts involved in the research argue that introducing cannabis during this phase may disrupt those processes in ways that differ markedly from the effects seen in adult users.
The endocannabinoid system, which cannabis compounds interact with, plays a role in regulating brain development. Its involvement in neural signaling means that external cannabinoids introduced through drug use could interfere with natural developmental signals, according to the findings cited by The Independent.
Broader context
The research arrives as cannabis becomes increasingly normalized and legally available in a growing number of countries and U.S. states. Public health officials in several jurisdictions have cited adolescent brain development as a primary justification for maintaining age restrictions even where adult use has been decriminalized or legalized.
Advocates for cannabis reform have generally supported age-based restrictions, though some critics of drug prohibition argue that legal regulation provides better tools for limiting youth access than criminalization does.
Researchers stressed that more longitudinal studies are needed to fully understand how early cannabis use affects cognitive trajectories over a lifetime. However, the current body of evidence, they said, is sufficient to warrant caution and clear public health messaging directed at young people and their families.
