Happy teen boy with friends

Substance Attitudes & Use

The number of Americans supporting the legalization of recreational use of marijuana (cannabis) products has been steadily increasing in recent years. In November 2016, California voters passed Proposition 64, also known as the Adult Use of Marijuana Act, legalizing the sale and distribution of cannabis in both a dry and concentrated form. 

Legalization in California followed similar ballots in Colorado, Washington, Massachusetts, and other states. Many voters based their decision on what psychiatrist and addiction specialist Kevin Hill calls the three myths in his book Marijuana, specifically, the myth that cannabis is not harmful, that it cannot lead to addiction, and that stopping the use of marijuana cannot cause withdrawal symptoms.

The legalization of cannabis use reinforced a low-risk perception that has been steadily filtering down to teens. According to the 2014 National Survey on Drug Use and Health, 51.5 percent of American teens aged 12–17 perceived great risk from smoking marijuana once or twice a week in 2002. Twelve years later that percentage had plummeted to only 37.4. That means more than 60 percent of teenagers do not consider smoking marijuana once or twice a week a great risk. A 2016 study from the National Institute on Drug Abuse (Monitoring the Future) found that marijuana was one of the most commonly used drugs among teens. Less than 20 percent of 18–25 year-olds believe that marijuana use is dangerous.

This perceived harmlessness can backfire, especially on heavy users, as Dr. Hill explains in Marijuana: “Excellent scientific research shows that regular marijuana use affects the ability to think, can increase feelings of anxiety and depression, and increases the odds that one will develop psychotic disorders such as schizophrenia.” And it can result in a cannabis use disorder, of course.

The vanishing risk perception is especially problematic for young people whose brains are not fully developed and who are more inclined to engage in risky behavior. Marijuana affects brain development. When people begin using marijuana as teens, the drug may impair thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions. 

Using marijuana depresses brain function to the point where chronic use results in lethargy and a reduction in motivation. The more potent the weed, the more lethargic the user. This is not good for anybody but unlike adults, the teen brain is still actively developing and often will not stop until the mid-20s. Drinking and drug use during this period can have a hugely detrimental impact, affecting a teen’s ability to progress and grow on numerous fronts.

Substances are regularly misdirected and misused to self-medicate the symptoms of mental health conditions like anxiety, depression, and mood disorders. Misusing drugs or alcohol in this way can make an underlying mental illness worse and lead to a substance use disorder requiring treatment.