LAS VEGAS (KLAS) — A group of doctors is urging states that allow legal recreational marijuana to push the minimum age for buyers to 25 or older.

In a recent New York Times editorial, they noted that marijuana can have a “deleterious impact on cognitive development in adolescents, impairing executive function, processing speed, memory, attention span, and concentration.” They cite long-term studies that show substantial negative effects of marijuana use on brain development of teens and young adults.

Retail marijuana was passed by Nevada voters in 2016, and legal sales began at licensed dispensaries in the summer of 2017. Like alcohol, marijuana buyers in Nevada must provide legal proof that they are 21 or older.

Sasha DeCania is the executive clinical director of Ignite Teen Treatment in Las Vegas, a residential facility which treats teens with mental health or substance abuse issues. She agrees lawmakers should explore raising the age to buy cannabis products.

“I think we have this misconception that cannabis is a drug from many years ago that you smoke and feel high and that’s over,” said DeCania. “But for many kids, it becomes chronic, daily use.”

DeCania said she has seen serious mental and physical health problems in adolescents that routinely use marijuana. She said doctors are still sorting out the long-term effects on brain development, and noted conative ability is not fully developed until a person’s mid-20’s.

“Laws don’t always prohibit people from using any type of substance,” said DeCania. “But I do agree that cannabis use chronically or frequently during brain development is detrimental.”

DeCania said alcohol and marijuana have vastly different effects on the body and brain and must be treated differently. She said it may not be appropriate to keep the same legal standard with both products.

The authors of the New York Times editorial said the risk marijuana poses to adolescents today is greater than in the 1990’s. They note the average THC of confiscated marijuana 20 or 30 years ago was roughly 3.7%, whereas the average content now is 18.7%.

In January Governor Steve Sisolak announced the creation of a Cannabis Compliance Board for Nevada. However, since retail sales of cannabis were legalized in Nevada, there has been no legislative push to change the minimum age for buyers.