Teenagers and young adults have easy access to marijuana, and many are using cannabis frequently and heavily. Chronic use of marijuana has higher risks to young people due to the developing teen brain. Dr. Shanna Garza reviews medical and mental health risks that are more significant in adolescents. Parents, listen to learn more about the possible effects heavy marijuana use can have for your teen and young adult children. There are higher rates of depression, anxiety, psychosis and schizophrenia, leading to a very significant negative impact on adolescent mental health.