A Columbia University study found that teens who use cannabis recreationally are two to four times more likely to develop psychiatric disorders, such as depression and suicidality, than teens who don’t use cannabis at all. 
 
The research also finds that casual cannabis use puts teens at risk for problem behaviors, including poor grades, truancy, and trouble with the law, which can have long-term negative consequences and may keep youth from developing their full potential in adulthood. Perceptions exist among youth, parents, and educators that casual cannabis use is benign, but studies show that is not the case. Cannabis use has strong associations to adverse mental health and life outcomes for teens who don’t necessarily have a substance abuse problem, difficulty thinking, problem-solving, and reduced memory, as well as a risk of long-term addiction.
 
Immature Brain Regions put Teens at Elevated Risk
Numerous studies note that exposing developing brains to cannabis can alter the development of the cerebral cortex, the brain’s center of reasoning and executive function. This poses a risk to young people whose brains have not matured and cause more susceptibility to developing other forms of addiction later in life.


Teens who feel depressed or suicidal may use cannabis as way to relieve their suffering, however using cannabis likely worsens depressive and suicidal symptoms. 
 
Teenage marijuana use is at its highest level in 30 years, and today's teens are more likely to use marijuana than tobacco. Many states allow recreational use of marijuana in adults ages 21 and over. Today's marijuana plants are grown differently than in the past and can contain two to three times more tetrahydrocannabinol (THC), the ingredient that makes people high. The ingredient of the marijuana plant thought to have most medical benefits, cannabidiol (CBD), has not increased and remains at about 1%. 
 
It is often difficult for parents to watch for cannabis use in their child because of the many ways it can be used:

• Smoking the dried plant (buds and flowers) in a rolled cigarette (joint), pipe, or bong
• Smoking liquid or wax marijuana in an electronic cigarette, also known as vaping
• Eating "edibles" which are baked goods and candies containing marijuana products
• Drinking beverages containing marijuana products
• Using oils and tinctures that can be applied to the skin 

Long-term use of marijuana can lead to:

• Cannabis Use Disorder
• The same breathing problems as smoking cigarettes (coughing, wheezing, trouble with physical activity, and lung cancer)
• Decreased motivation or interest which can lead to decline in academic or occupational performance
• Lower intelligence
• Mental health problems, such as schizophrenia, depression, anxiety, anger, irritability, moodiness, and risk of suicide 
• Tips on discussing marijuana with your child: Ask what they have heard about using marijuana. Listen carefully, pay attention, and try not to interrupt. Avoid making negative or angry comments.
• Offer your child facts about the risks and consequences of smoking marijuana.
• Ask your child to give examples of the effects of marijuana. This will help you make sure that your child understands what you talked about.
• If you choose to talk to your child about your own experiences with drugs, be honest about why you used and the pressures that contributed to your use. Be careful not to minimize the dangers of marijuana or other drugs and be open about any negative experiences you may have had. Given how much stronger marijuana is today, its effect on your child would likely be much different than what you experienced.
• Explain that research tells us that the brain continues to mature into the 20s. While it is developing, there is greater risk of harm from marijuana use.

Parents and Prevention
Parents can help their children learn about the harmful effects of marijuana use. Talking to your children about marijuana at an early age can help them make better choices and may prevent them from developing a problem with marijuana use later. Begin talking with your child in an honest and open way when they are in late elementary and early middle school. Youth are less likely to try marijuana if they can ask parents for help and know exactly how their parents feel about drug use. 
 
If your child is already using marijuana, try asking questions in an open and curious way as your teen will talk more freely if not feeling judged. 
 
If you have concerns about your child's drug use, please talk with your child's Care Team.
 
Resources:
https://www.columbiapsychiatry.org/news/recreational-cannabis-use-among-u-s-adolescents-poses-risk-adverse-mental-health-and-life-outcomes#:~:text=A%20Columbia%20University%20study%20has,t%20use%20cannabis%20at%20all.
https://www.samhsa.gov/sites/default/files/TTHY-Marijuana-Broch-2020.pdf
https://childmind.org/article/talk-teenager-substance-use-abuse/
 
Source:
AACAP
Columbia University