Teens who use cannabis may face a substantially higher risk of developing serious mental health conditions, including psychotic disorders and bipolar disorder, according to a study of more than 463,000 adolescents published in the journal Addiction.
Study scope and findings
Researchers analyzed health records and survey data from adolescents aged 12 to 18 over a five-year period. After controlling for socioeconomic status, family history of mental illness, and other substance use, they found that cannabis users had a 96% higher risk of developing a psychotic disorder and an 82% higher risk of bipolar disorder compared to non-users. The risk increased with frequency of use.
Dose-response relationship
Weekly users faced higher risks than monthly users, and daily users faced the highest risks of all. 'This is not a subtle effect,' said lead author Dr. Sarah Chen. 'The data show a clear dose-response relationship. The more frequently a teen uses cannabis, the greater their risk of a serious psychiatric diagnosis.'
Policy implications
With cannabis legalization expanding across US states and other countries, the findings carry weight for public health policy. The study's authors recommend that pediatricians screen all adolescent patients for cannabis use and that legalization frameworks include age restrictions and public health warnings about mental health risks.