The average amount of THC, the psychoactive ingredient in marijuana samples seized by law enforcement agencies is 15% compared to 4% in 1980. This means that marijuana today is more than 2 ½ times more potent than it was 30 years ago. The increase of THC translates to stronger effects on the developing teenage brain and an increased risk of dependency. It accounts for a greater chance of adverse or unpredictable reactions. NIDA. Drug Facts: Marijuana.
Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ. American Psychological Association. Regular Marijuana Use Bad for Teens' Brains.
Imaging scans also found detectable differences in how their brains worked. Imaging scans found alterations in the frontal cortex of the brain in youth that begin using marijuana at an earlier age that are associated with increased impulsiveness. The frontal cortex is the last part of the brain to come online, and the most important. Early exposure perhaps changes the trajectory of brain development, such that ability to perform complex executive function tasks is compromised. New York Times. Legalizing of Marijuana Raises Health Concerns
Young adults who started smoking pot regularly before they were 16 performed significantly worse on cognitive tests of brain function than those who had started smoking later in adolescence. They performed particularly poorly on tests assessing executive function, which is responsible for planning and abstract thinking, as well as understanding rules and inhibiting inappropriate responses. A long term study in New Zealand showed regular pot smokers lost an average of 8 IQ points. The lost cognitive abilities were not restored in those who quit smoking. New York Times. Legalizing of Marijuana Raises Health Concerns
Marijuana’s negative effects on attention, memory, and learning can last for days and sometimes weeks. Marijuana’s effects can make it difficult not only to learn something new, but to do the complex tasks that require focus and concentration or the stringing together of information sequentially. NIDA. Marijuana: Facts for Teens
Just as teens do not perceive great risk from smoking marijuana, many also say they are more careful when driving a car. The facts are that marijuana and driving don’t mix. Marijuana significantly impairs judgment, motor coordination, and reaction time – all essential skills for safe driving. Studies have found a direct relationship between blood THC concentration and impaired driving ability. Teens who smoke and drive put themselves and their passengers at greater risk of harm. NIDA. Does Marijuana Use Affect Driving?
Within a few minutes after inhaling marijuana smoke, a person’s heart rate speeds up, the bronchial passages (the pipes that let air in and out of your lungs) relax and become enlarged, and blood vessels in the eyes expand, making the eyes look red. While these and other effects seem harmless, they can take a toll on the body.
When someone uses marijuana, heart rate — normally 70 to 80 beats per minute—may increase by 20 to 50 beats per minute or, in some cases, even double. This effect can be greater if other drugs are taken with marijuana. The increased heart rate forces the heart to work extra hard to keep up.
Smoke from marijuana irritates the lungs, causing breathing and lung problems among regular users similar to those experienced by people who smoke tobacco — like a daily cough and a greater risk for lung infections such as pneumonia.
Marijuana increases the risk of mental health problems. Marijuana use has been linked with depression and anxiety, as well as suicidal thoughts among adolescents. In addition, research has suggested that in people with a genetic risk for developing schizophrenia, smoking marijuana during adolescence may increase the risk for developing psychosis and schizophrenia at an earlier age. Researchers are still learning exactly what the relationship is between these mental health problems and marijuana use. NIDA. Marijuana Facts for Teens.
About 4 in 5 (79.9%) 12- to 17-year-olds in Rhode Island in 2012 perceived no great risk from smoking marijuana once a month – a rate higher that the national rate. Also, the percentage of RI youths perceiving no great risk from marijuana use once a month increased from 2008 to 2012. SAMHSA. Behavioral Health Barometer: Rhode Island 2013.