Marijuana Use Is Going Up
A recent studies from Florida Atlantic University spanning 16 years (2003–2019) reports that while many more Americans meet criteria for Cannabis Use Disorder (CUD), the share of people receiving treatment for it has declined. In 2003 about 19% of people with CUD got treatment; by 2019 that dropped to about 13%.
The increased use of marijuana is consistent with reports that suggest that daily use of marijuana is now outpacing daily use of alcohol. Still, it is shocking to hear that 18 million people use marijuana every day, or nearly every day.
A second FAU-linked study (2025) focused on adolescents (ages 12–17) who attempted treatment for CUD: among 40,000+ teens treated between 2018–2021, only ~35% completed treatment.
Many of those teens began using cannabis at very young ages (between 12 and 14), often alongside other mental health or substance-use problems, which complicates recovery and increases risk.
The dangers of brain damage from regular use of marijuana is particularly acute for people under the age of 25. That is because the human brain continues to undergo significant development until approximately age 25, with the prefrontal cortex—the region responsible for executive functions like decision-making, impulse control, risk assessment, and long-term planning—being one of the last areas to fully mature.
High potency THC products act primarily on the endocannabinoid system, which plays a critical role in regulating synaptic pruning and neural connectivity. Heavy or frequent exposure during this developmental window can disrupt normal pruning, leading to reduced gray-matter volume in areas like the prefrontal cortex, hippocampus, and amygdala.
Longitudinal studies show that individuals who begin regular cannabis use before age 18–20 experience greater declines in IQ (averaging 6–8 points by adulthood), poorer working memory, slower processing speed, and impaired attention compared to later-onset or non-users, even after controlling for confounding factors like alcohol use and socioeconomic status.
This is why public-health organizations (including the American Academy of Pediatrics, CDC, and WHO) identify adolescence and early adulthood as a period of heightened neurodevelopmental risk from regular cannabis use, with earlier and heavier use associated with greater likelihood of lasting cognitive deficits, increased risk of psychosis in genetically vulnerable individuals, and lower educational and occupational attainment.
Yet, there may be a bit of good news in the FAU study: Their recent study actually demonstrates a decline in marijuana use among young people.
