Know the Facts: Marijuana and Youth – How it Affects Your Brain and Body
What Are the Short-Term Effects of Marijuana Use?
For some people, smoking marijuana makes them feel good. Within minutes of inhaling, a user begins to feel “high,” or filled with pleasant sensations. THC triggers brain cells to release the chemical dopamine. Dopamine creates good feelings—for a short time. But that’s just one effect…
Imagine this: You're in a ball game, playing out in left field. An easy fly ball comes your way, and you're psyched. When that ball lands in your glove your team will win, and you'll be a hero. But, you're a little off. The ball grazes your glove and hits the dirt. So much for your dreams of glory.
Such loss of coordination can be caused by smoking marijuana. And that's just one of its many negative effects. Marijuana affects memory, judgment, and perception. Under the influence of marijuana, you could fail to remember things you just learned, watch your grade point average drop, or crash a car.
Also, since marijuana can affect judgment and decision making, using it can cause you to do things you might not do when you are thinking straight—such as engaging in risky sexual behavior, which can result in exposure to sexually transmitted diseases, like HIV, the virus that causes AIDS, or getting in a car with someone who’s been drinking or is high on marijuana.
It’s also difficult to know how marijuana will affect a specific person at any given time, because its effects vary based on individual factors: a person’s genetics, whether they’ve used marijuana or any other drugs before, how much marijuana is taken, and its potency. Effects can also be unpredictable when marijuana is used in combination with other drugs.
THC Affects Brain Functioning
THC finds brain cells, or neurons, with specific kinds of receptors called cannabinoid receptors and binds to them.
Certain parts of the brain have high concentrations of cannabinoid receptors. These areas are the hippocampus, the cerebellum, the basal ganglia, and the cerebral cortex. The functions that these brain areas control are the ones most affected by marijuana.
For example, THC interferes with learning and memory—that is because the hippocampus—a part of the brain with a funny name and a big job—plays a critical role in certain types of learning. Disrupting its normal functioning can lead to problems studying, learning new things, and recalling recent events. The difficulty can be a lot more serious than forgetting if you took out the trash this morning, which happens to everyone once in a while.
Do these effects persist? We don’t know for sure, but as adolescents your brains are still developing. So is it really worth the risk?
Smoking Marijuana Can Make Driving Dangerous
The cerebellum is the section of our brain that controls balance and coordination. When THC affects the cerebellum’s function, it makes scoring a goal in soccer or hitting a home run pretty tough. THC also affects the basal ganglia, another part of the brain that’s involved in movement control.
These THC effects can cause disaster on the road. Research shows that drivers on marijuana have slower reaction times, impaired judgment, and problems responding to signals and sounds. Studies conducted in a number of localities have found that approximately 4 to 14 percent of drivers who sustained injury or death in traffic accidents tested positive for THC.
Marijuana Use Increases Heart Rate
Within a few minutes after inhaling marijuana smoke, an individual's heart begins beating more rapidly, the bronchial passages relax and become enlarged, and blood vessels in the eyes expand, making the eyes look red. The 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.
What Are the Long-Term Health Effects of Marijuana Use?
When people smoke marijuana for years, they can suffer some pretty negative consequences. For example, because marijuana affects brain function, your ability to do complex tasks could be compromised, as well as your pursuit of academic, athletic, or other life goals that require you to be 100-percent focused and alert. In fact, people who use marijuana over the long term report less life satisfaction, poorer education, and job achievement, and more interpersonal problems compared to people who do not use marijuana.
Marijuana also may affect your mental health. Studies show that early marijuana use may increase your risk of developing psychosis if you have a genetic vulnerability to the disease. Psychosis is a severe mental disorder in which there is a loss of contact with reality, including false ideas about what is happening (delusions) and seeing or hearing things that aren’t there (hallucinations). Marijuana also has been associated with depression and anxiety, but more research is necessary to confirm and better understand that relationship.
Many people don’t think of marijuana as addictive—they are wrong. About 9 percent of people who use marijuana become dependent on it. The number increases to about one in six among those who start using it at a young age, and to 25 to 50 percent among daily users. Marijuana increases dopamine, which creates the good feelings or “high” associated with its use. A user may feel the urge to smoke marijuana again, and again, and again to re-create that experience. Repeated use could lead to addiction—a disease where people continue to do something, even when they are aware of the severe negative consequences at the personal, social, academic, and professional levels.
People who use marijuana may also experience a withdrawal syndrome when they stop using the drug. It is similar to what happens to tobacco smokers when they quit—people report being irritable, having sleep problems, and weight loss—effects which can last for several days to a few weeks after drug use is stopped. Relapse is common during this period, as users also crave the drug to relieve these symptoms.
Lungs and Airways
People who abuse marijuana are at risk of injuring their lungs through exposure to respiratory irritants and carcinogens found in marijuana smoke. The smoke from marijuana contains some of the same chemicals found in tobacco smoke; plus, marijuana users tend to inhale more deeply and hold their breath longer, so more smoke enters the lungs. Not surprisingly, people who smoke marijuana have some of the same breathing problems as those who smoke tobacco—they are more susceptible to chest colds, coughs, and bronchitis than people who do not smoke. And, even though we don’t know yet whether or how marijuana use affects the risk for lung and other cancers—why take the risk?
1. National Institute on Drug Abuse. Marijuana: Facts for Teens(http://www.drugabuse.gov/publications/marijuana-facts-teens).NIH Pub. No. 04-4037. Bethesda, MD. NIDA, NIH, DHHS. Revised March 2011. Retrieved February 2012.
2. National Institute on Drug Abuse. Marijuana: Facts Parents Need to Know (http://www.drugabuse.gov/publications/marijuana-facts-parents-need-to-know). NIH Pub. No. 07-4036. Bethesda, MD. NIDA, NIH, DHHS. Revised March 2011. Retrieved February 2012.
3. National Institute on Drug Abuse. Monitoring the Future. National Results on Adolescent Drug Use. Overview of Key Findings 2011.
4. National Institute on Drug Abuse. NIDA Research Report: Marijuana Abuse (http://www.drugabuse.gov/ResearchReports/Marijuana/
default.html). NIH Pub. No. 10-3859. Bethesda, MD. NIDA, NIH, DHHS. Revised September 2010. Retrieved February 2012.
5. National Institute on Drug Abuse. Monitoring the Future. Data Tables and Figures
Bethesda, MD. NIDA, NIH, DHHS. December 2011. Retrieved February 2012.
October is National Substance Abuse Prevention Awareness Month. The Novato Blue Ribbon Coalition for Youth’s mission is to positively impact the well-being of Novato youth through community action, policy advocacy and education. This shall be accomplished by, 1. Reducing alcohol and marijuana use, and 2. Reducing incidences of bullying.
Please join us at our next Coalition meeting on November 14, 2012 from 6:30-8:00 pm at Novato City Hall – 901 Sherman Avenue.
For more information regarding the Novato Blue Ribbon Coalition for Youth, please contact Nikki Buckstead at 415-798-5329 or firstname.lastname@example.org