It is not uncommon for me to hear parents discuss their teen’s marijuana use. While some are concerned many shrug it off as a relatively benign activity, often offering their own marijuana use in high school or college as an example of safety. However, personal anecdotes are not the best proof that something is relatively risk-free. I never wore a seat belt until middle school and was never injured in a car accident, but I would not offer that up as proof that seat belts are overrated.
In 2016 approximately 35 percent of high school seniors and 10 percent of eighth-grade students reported marijuana use in the past year with 1 in 16 seniors — or 6 percent — reporting daily marijuana use. If you know a teen or have a teen and he or she hasn’t used marijuana chances are the teens will know someone who has. Only 31 percent of 12th graders believe that regular use of marijuana among teens is harmful, so lack of concern about risks is common and definitely a contributing factor.
Botanical marijuana, Cannabis sativa, contains more than 60 pharmacologically active cannabinoids. While the medical benefits are often widely promoted studies are generally sparse. There is data supporting use for some types of chronic pain and muscle spasticity and both tetrahydrocannabinol (THC), the main psychoactive ingredient, and cannabidiol (CBD) have an impact on nausea and are often used to treat the nausea and vomiting of chemotherapy. CBD is believed to offer the benefit for chronic pain.
After inhalation, THC concentrations rise rapidly in the blood stream and even a single inhalation of a low-dose marijuana cigarette (16 mg THC) produces measurable levels. After oral ingestions THC is digested in the stomach and travels to the liver where it undergoes metabolism before entering the blood stream. This results in a slower and lower peak in blood THC levels with edibles.
STORED IN FATTY TISSUE
THC is a lipid, which means it is a fatty molecule, so it is deposited in fat-creating stores that slowly re-enter the circulation over time. Chronic smokers will have significantly higher levels of THC compared with infrequent users as they have greater stores of THC in their fatty tissue. THC levels in brain tissue are higher than in blood and persist even after it has cleared from the blood stream.
Doses of THC in marijuana have increased dramatically, rising from 4 percent in 1995 to 12 percent in 2014. Labs in Colorado have reported THC concentrations as high as 30 percent in some strains. This is a different marijuana from what parents today may have used themselves as teenagers. While some people search for low THC/high CBD strains, the labeling of these products is often incorrect and strains that are sold as low in THC are often the exact opposite. Concentrated oils and waxes, often used for vaporization or dabbing, may have THC concentrations as high as 80 percent, and many have significant amounts of potentially harmful solvent residue such as butane.
The body and brain are filled with endocannabinoid receptors and we still do not fully understand this complex system or the impact of stimulating developing tissues that contain these receptors with the cannabinoids in marijuana. The teenage brain, especially the prefrontal cortex, which is responsible for decision making, is not fully developed until the early 20s. Studies looking at brain function show abnormalities among youth who use cannabis as little as 10 times a month. A long-term study that involved neuropsychiatric testing found marijuana use in adolescence had an impact on many neuropsychological domains, including intellectual function, and a full recovery did not happen even after discontinuing use.
RISK OF ADDICTION
Regular use of marijuana as a teen may increase the risk of depression and psychosis, and the risk of addiction is almost double when marijuana is started as a teen versus as an adult (17 percent versus 9 percent). Among teenagers who smoke marijuana daily, 25 to 50 percent will become addicted.
The American Academy of Pediatrics has a variety of recommendations when it comes to marijuana and teens. The organization wants parents to know that using marijuana in front of teens increases the likelihood that their teenager will also use marijuana. In addition, marijuana smoke has harmful chemicals and so smoking in front of teenagers also presents this hazard.
It is unclear how state legalization of marijuana for adults will impact teen use in California. Colorado saw no increase in teen use after legalization, but in Washington marijuana use increased among eighth- and 10th-graders post legalization. The possibility for increased used among teens in California post-legalization exists, and parents, schools, and health-care providers should be prepared.
What is known is that today’s marijuana has far more THC than 20 or even 10 years ago and some methods of recreational use deliver astonishingly high levels of it. Solvents that may be used to prepare some forms may offer other health risks. The developing brain seems vulnerable to negative and potentially permanent consequences from marijuana and adolescent use also increases the risk of addiction.
I’ve already started clear discussions with my teens about these risks because I want my factual information to be ahead of all of the other messages they are going to hear from their peers or read about online.
Dr. Jen Gunter is a Marin resident and an ob/gyn in San Francisco. Her column appears every fourth week.
credit:marinij.com
