Marijuana and the teenage brain

The rise in marijuana’s accessibility — and soon to be legality — has decreased the stigma of this controlled substance. While more physicians may soon consider its use for specific medical conditions, the socialization of the drug may have downplayed its dangers on the teenage brain.

The danger exists because the brain’s executive function – the part of the brain responsible for reasoning, problem solving, and planning – is not fully developed until a teen’s mid-20s.

Studies over the past three years have linked regular teen marijuana use (which is considered once a week) to memory loss, real or perceived lower IQ, increased risk of mental disorders, car accidents, addiction, and chronic bronchitis. But that hasn’t stopped teens from inhaling and ingesting.

The Canadian Medical Association says Canadian youth (aged 15 to 24) has the highest rate of marijuana use among 29 developed countries. Almost a quarter of the population aged 15 to 24 years reported past-year use.

Teens usually smoke for two reasons: recreation and managing anxiety. Dr. Mark Rothman, Clinical Psychologist for Child and Youth at Medcan, says regardless of the reason, any type of dependency can lead to unintended consequences.

Cannabis use is an unreliable coping strategy

“Any time someone uses anything external as a way to cope more effectively – be it alcohol, video games, internet, drugs – if people are using them as a primary coping strategy, development of other coping strategies (like communication skills, time and energy management, stress management or exercise) is weakened,” says Dr. Rothman.

“Dependency on using that substance increases. A teen with anxiety who self medicates with pot will likely start using it more frequently for that purpose, and then will develop other problems that they didn’t foresee. Maybe they were using marijuana to help with social anxiety, but it can cause school issues to arise, or money or health issues to develop. So instead of one problem solved, they develop six more.”

Dr. Rothman cites alternative strategies for anxiety, such as cognitive behavioural therapy, improved sleep and eating habits, a diagnosis and/or a prescription of right medication by a physician.

Marijuana use in teens increases chances of psychosis and mental disorders

In addition to derailing reliable coping strategies, frequent marijuana use can have a destabilizing effect on a teen’s mental health. Often psychosis can be triggered earlier in marijuana users if they are predisposed to mental disorders, or are genetically likely to develop psychosis.

“Teens using weed have experienced increased mental health concerns or new mental health symptoms such as depression, anxiety, paranoia, or hearing voices,” says Chantal Wiggins-McKinnon, a registered nurse and Program Lead, Child and Youth at Medcan.

Cannabis use in teens has been linked to increased cases of delusion, psychosis and hallucinations.

“There is evidence of serious harms including poor psychological function, increased anxiety, depression and psychosis,” says Dr. Janice Weiss, Director of the Child and Youth Program at Medcan. “There is an association of cannabis use and development of schizophrenia in later years.”

“Cannabis has significant impact on the developing brain, especially when used under 25 years of age,” adds Dr. Weiss. “While we understand that teens are interested in using it to alleviate symptoms associated with mental health concerns, we really do recommend that those concerns are best treated through proper diagnosis and psychiatric care.”