Marijuana is the most commonly used illicit substance among adolescents — the illegal drug they have used most widely for over 40 years. In the 2015 edition of a national annual study of high schoolers from the University of Michigan, almost 40 percent of high school seniors responded that they have smoked marijuana in the past year, and one in 17 reported smoking it daily. Additionally, 80 percent of seniors stated that marijuana is fairly easy to obtain, with its perceived risks at an all-time low: Only 35 percent called using it regularly a “great risk.”
Substance abuse by adolescents is an ongoing health concern. Marijuana remains classified in the Controlled Substances Act as a Schedule I drug, implying that it has a high potential for abuse, has no currently accepted medical use and is unsafe for use under supervision by a physician. Despite this classification, marijuana has been legalized for medical purposes in a number of states, in direct opposition to federal law.
Studies have demonstrated the potential negative consequences of short- and long-term recreational use of marijuana in adolescents. Smoking marijuana has negative effects on lung function, and studies have linked marijuana use with higher rates of psychosis in patients with a predisposition to schizophrenia.
The adolescent brain, particularly the prefrontal cortex areas controlling judgment and decision-making, is not fully developed until people are in their mid-20s, raising questions about how any substance use may affect its development. The younger an adolescent begins using drugs, including marijuana, the more likely it is that drug dependence or addiction will develop in adulthood. A recent analysis of four large trials found that marijuana use during adolescence is associated with reductions in the odds of a student completing high school, and increases in the use of other illicit drugs and suicide attempts in a dose-dependent fashion — suggesting that marijuana use is causative.
Marijuana is a complex mixture of biologically-active cannabinoids (more than 200 have been identified) and other molecules, and the risk-benefit ratio of this mixture has not been well defined. Over the past several decades, selective breeding of marijuana species has resulted in higher concentrations of cannabinoids in the plant, resulting in a more potent psychotropic effect and possible increased risk of adverse results. Any product that requires smoking to release the desired effects cannot be recommended by physicians, because smoke contains tar and other harmful chemicals.
In November, Missouri voters will face three ballot initiatives that would legalize medical marijuana, each under different circumstances. Informed voters should consider these recommendations before voting yes:
▪ Given the data indicating negative effects of marijuana on the health and brain development of children and adolescents, even medical marijuana should not be used on them, even when given by parents. (Abuse and neglect can occur when adults are high themselves.)
▪ Medical marijuana should not be used outside the U.S. Food and Drug Administration regulatory process. Cannabidiol or CBD, an extract of the marijuana plant, may be an option for children with life-limiting or severely debilitating conditions for whom current therapies are inadequate. However, remember that cannabidiol without THC, the ingredient in marijuana that gets people high, is currently legal in Missouri on a restricted basis.
▪ Marijuana is associated with adverse health effects such as lung damage and addiction.
▪ Medical marijuana provides levels of THC that can cause seizures. Thus, laws that aim to help intractable seizures should not include the use of medical marijuana, as this drug may worsen the condition.
Jennifer Lowry is chief toxicologist at Children’s Mercy Hospital and a member of The Star’s Missouri Influencers panel.