U.S. Surgeon General’s Warning on Marijuana Use and the Developing Brain
On August 29, the U.S. Surgeon General issued a new advisory on marijuana use and the developing brain. The advisory focuses on the dangers of marijuana for adolescents and for pregnant women.
The statement from Surgeon General Vice Adm. Jerome Adams emphasized “the importance of protecting our Nation from the health risks of marijuana use in adolescence and during pregnancy. Recent increases in access to marijuana and in its potency, along with misperceptions of safety of marijuana endanger our most precious resource, our nation’s youth.”
Two major changes in recent years are contributing to increased use of marijuana and greater risks from its use. Marijuana is more available and acceptable as a growing number of states legalize its use by adults for medicinal or recreational purposes. The Surgeon General notes that the marijuana available today is much more potent than in the past. Typical concentration of Delta-9-tetrahydrocannabinol (THC), a component of marijuana, increased three-fold between 1995 and 2014. Higher doses of THC increase the risks of physical dependence and addiction and are more likely to lead to anxiety, agitation, paranoia and psychosis.
Marijuana is commonly used by youth and young adults—in 2018 an estimated one in eight (12.5%) youth 12 to 17 years old and more than one in three (34.8%) young adults aged 18 to 25 had used marijuana. (SAMHSA 2019) Frequent marijuana use during adolescence can impair learning and is associated with changes in the areas of the brain involved in attention, memory, decision-making and motivation. It is also associated with a risk of schizophrenia and other psychotic disorders. Adolescents are at particular risk for cannabis use disorder and can experience significant withdrawal symptoms. An estimated one in six daily users become dependent on cannabis. (APA Resource Document)
A 2019 APA position statement notes similar concerns: “There is no current scientific evidence that cannabis is in any way beneficial for the treatment of any psychiatric disorder. In contrast, current evidence supports, at minimum, a strong association of cannabis use with the onset of psychiatric disorders. Adolescents are particularly vulnerable to harm, given the effects of cannabis on neurological development . . . There is great variability of in the form, dose and potency of cannabis. Furthermore, there are numerous other compounds in products marketed as cannabidiol or cannabis with unknown health effects.”
Use of marijuana by pregnant women has increased in recent years. Marijuana use during pregnancy can affect the developing fetus and is associated with adverse outcomes, including lower birth weight. Both the American College and Obstetricians and Gynecologists and the American Academy of Pediatrics recommend against marijuana use by pregnant women. Harmful effects of marijuana use can also be passed on to a newborn through breast milk. It can affect the newborn’s brain development and contribute to hyperactivity, poor cognitive function or other problems.
- APA Position Statement In Opposition to Cannabis as Medicine (2019)
- APA Position Statement Against the Use of Cannabis for PTSD (2019)
- APA Resource Document, Opposition to Cannabis as Medicine (2018)
- APA Position Statement on Need to Monitor and Assess the Public Health and Safety Consequences of Legalizing Marijuana
- Substance Abuse and Mental Health Services Administration, 2019, Results from the 2018 National Survey on Drug Use and Health