As marijuana use among teens has surged over the last decade, researchers are becoming increasingly concerned about its health risks. A new study reveals that using cannabis at a young age can lead to significant mental health issues later on, including bipolar disorder, psychotic disorders, anxiety, and depression.
Study Insights
The study analyzed data from about 460,000 teenagers in California’s Kaiser Permanente Health System. These teens were tracked until they turned 25 and underwent annual screenings for substance use and mental health conditions. Notably, researchers focused on those who had no symptoms of mental illness before using cannabis.
Dr. Lynn Silver, a pediatrician involved in the study, emphasized that the results suggest a clear link between early cannabis use and later mental health disorders. Teens who used cannabis had twice the risk of developing serious conditions like bipolar disorder and schizophrenia compared to those who didn’t use it.
“It’s really concerning,” shared Dr. Ryan Sultan, a psychiatrist at Columbia University. He noted increasing instances of teens developing new or worsening mental health problems that coincide with cannabis use.
The Bigger Picture
While nearly 4,000 teens in the study were diagnosed with serious disorders, the societal impact is far-reaching. The cost of treating schizophrenia alone is estimated at $350 billion annually in the U.S. Silver warned that an increase in cannabis-related health issues could offset the economic benefits of the expanding cannabis market.
Additionally, the study found that cannabis users also had a 33% higher risk of developing depression and a 25% higher risk for anxiety. Interestingly, the younger the teen was when they started using cannabis, the stronger the link to these disorders. This highlights the sensitivity of the developing adolescent brain to cannabis effects.
Historical Context
Historically, marijuana was often seen as a harmless substance, especially with recent legalizations across various states. However, this new research challenges that perception, revealing that cannabis isn’t as safe as many young people think. With increasing legalization, the notion of cannabis as a natural remedy for stress has gained popularity, but researchers urge caution.
Past studies have established a connection between cannabis use and mental health issues, but many failed to clarify whether drug use causes these conditions or if individuals with existing issues are more likely to seek out cannabis. This latest study, by excluding those already showing symptoms, provides stronger evidence for causality.
Expert Opinions
Experts like Sultan and Silver agree that mental health disorders often stem from a complex interplay of genetics, environment, and personal experiences. They suggest that individuals prone to mental health issues should avoid cannabis, as using it can exacerbate symptoms.
“Teens are essentially playing with fire,” Sultan cautioned. If they develop psychotic or severe mood disorders tied to cannabis use, it can hinder their ability to recover. Severe symptoms like those seen in bipolar disorder can drastically affect brain health and worsen over time.
Conclusion
The findings from this study are a crucial reminder for teens, parents, and educators about the real risks of cannabis use. As marijuana becomes more accepted in society, it’s essential to understand its potential impacts on mental health. Continued research is necessary, but for now, the evidence strongly suggests that early cannabis use can have serious long-term consequences on mental well-being.
For more details on the study and its implications, you can check the full research published in JAMA Health Forum here.

