Many people still believe marijuana is “safe” or that it’s impossible to get addicted, but research increasingly proves the opposite. Cannabis use disorder (CUD) is emerging as a serious public health issue in the United States and beyond. Unlike casual perceptions that downplay its risks, science shows cannabis can have long-lasting effects on the brain, behavior, and overall health—especially for teens and young adults whose brains are still developing. The rise of high-potency cannabis products has only made the problem worse, with stronger THC levels leading to greater dependency risks, more severe withdrawal symptoms, and higher rates of psychiatric conditions. What was once thought of as a harmless recreational drug is now linked with increased rates of hospitalization, cognitive impairment, depression, and even premature death.
Key Facts:
- A U.S. study of over 110 million people found states with legalized medical cannabis had a 42.7% increase in cannabis use disorder (CUD) and nearly double the rate of poisonings.
- A 2025 JAMA study showed people hospitalized for CUD faced a 3x higher risk of death within 5 years.
- In Canada, hospitalizations for CUD rose by 270% after legalization, alongside more psychosis and schizophrenia-related cases.
- THC levels have quadrupled since the 1990s, rising from under 4% to more than 16% today.
- Heavy cannabis use is tied to depression, suicidality, impaired working memory, and poorer school performance, especially among teens and young adults.
Taken together, these findings reveal a troubling reality: cannabis use disorder is real, widespread, and worsening. Addiction risks, mental health harms, and long-term consequences are being documented globally. Prevention, education, and treatment are urgently needed to protect young people and communities from the rising harms of cannabis use.
