Why 25? Doctors warn against the negative impact of cannabis use on young adult brains
It’s not your parents’ weed. That’s what doctors want young adults to know before they choose to consume marijuana, now decriminalized in Connecticut for people 21 and older.
“The THC [tetrahydrocannabinol] content of cannabis in the ’60s was about 3% to 4%,” said Dr. Deepak Cyril D’Souza, professor of psychiatry at the Yale University School of Medicine and director of the Schizophrenia Neuropharmacology Research Group at Yale.
“Now the average THC content is about four times higher,” he said. “And there is converging lines of evidence to suggest that exposure to cannabis may contribute to a higher risk of the development of what is [the] most serious of serious mental illnesses.”
D'Souza is talking about schizophrenia, which typically appears between the ages of 15 and 24.
D’Souza emphasized that he does not oppose decriminalization of marijuana, but he is deeply concerned about its commercialization. He pointed to parallels in the alcohol and tobacco industries, and the global disease burden as a result of alcohol and tobacco consumption: top 10 worldwide.
As early as 2019, D’Souza raised concerns with state lawmakers about the risk of marijuana on the developing brain, which doesn’t conclude until the age of 25.
The data on new onset psychosis with cannabis consumption, and even a drop in IQ among young adults, prompted doctors to push lawmakers to make 25 the legal age for cannabis consumption. Among those doctors is Gregory Shangold at the Connecticut State Medical Society, which is against the current legislation.
“In general people think it’s just a safe drug,” said Shangold, an emergency physician. “We’ve been seeing a lot of people come into the emergency department with acute toxicity effects of THC.”
Yale pediatrician Deepa Camenga, who specializes in adolescent medicine, said young people are better off waiting until they are at least 25 before deciding whether they want to try cannabis.
Camenga is also concerned that people who cannot afford to purchase cannabis at medical dispensaries will turn to the unregulated market.
“This cannabis may be marketed as being from a dispensary, but there really is no way to know,” she said.