Teenagers who report using cannabis are more likely to later receive a serious mental health diagnosis, according to a Kaiser Permanente study that was recently published in JAMA Health Forum.
The results add to an increasing body of research identifying health concerns related to cannabis use, particularly among vulnerable groups, including pregnant people and adolescents.
The study’s lead author, Kelly Young-Wolff, PhD, MPH, a clinical psychologist and research scientist with the Division of Research, discusses the study’s key findings, what the science says about using cannabis to manage depression or anxiety, guidance for parents, and why clinicians should identify and support teens who use cannabis.
Tell us about your research and what you learned.
We found that teens who reported cannabis use were more than twice as likely to later be diagnosed with a psychotic or bipolar disorder, 34% more likely to be diagnosed with a depressive disorder, and 24% more likely to be diagnosed with an anxiety disorder.
The findings are based on analyzing medical records of 463,396 adolescents from diverse racial and ethnic backgrounds in Northern California who were ages 13 to 17. They were followed up to age 25.
Of the total, 5.7% reported using cannabis in the previous year. These reports came from responses to a confidential screening questionnaire completed by patients during routine pediatric checkups.
How do you know whether the cannabis use causes the mental health disorders, or if teens are using the substance to manage their existing symptoms?
We can’t definitively conclude that cannabis causes mental health disorders, but these results suggest that cannabis use during adolescence is associated with increased risk.
We designed the study to reduce the possibility that teens were using cannabis to self-medicate existing mental health conditions. For example, we excluded teens who had already received a mental health diagnosis before reporting cannabis use. On average, mental health conditions were diagnosed in our sample about 2 years after a teen reported past-year cannabis use.
While many individuals report using cannabis to manage physical or emotional symptoms, such as sadness or nausea, growing evidence shows that cannabis is not an effective treatment for depression or anxiety. In fact, people who use cannabis regularly often experience worsening mood symptoms and are less likely to consistently engage in treatment.
What do you hope others will take away from the results?
The safest message for teens is to avoid cannabis use. It’s also important to recognize that many cannabis products available today have higher concentrations of THC, the primary psychoactive component, than products available in the past. And adolescents are biologically more vulnerable to the effects of substances like cannabis than adults.
For parents, our advice is to stay calm, maintain open communication with your teens, and seek support early if concerns arise. Your child’s health care team can be an important resource.
For clinicians, these results reinforce the importance of routine, confidential screening for substance use to help identify teens who may benefit from additional support and early intervention within the health care system.
