Marijuana legalization poses a significant health risk to America’s youth—and many parents have no clue about the consequences, says a former Obama administration drug policy adviser.

“Today’s marijuana is not the marijuana of the ‘60s, ‘70s or ‘80s. It’s five to 15 times stronger,” Kevin Sabet said in an exclusive interview with The Foundry. “I think a lot of Baby Boomers’ experience with pot—a couple of times in the dorm room—they don’t correspond to what kids are experiencing today.”

Sabet, a former senior adviser at the White House Office of National Drug Control Policy, wrote the book “Reefer Sanity: Seven Great Myths About Marijuana” to shed light on the marijuana legalization movement.

He pointed to Colorado, which has operated with de-facto legalization for five years, as a case study. By 2011, Denver had more medical marijuana shops than Starbucks or McDonalds.

The state has more kids using marijuana, he said, resulting in more kids in treatment and higher rate of car crashes. There have even been two deaths tied to marijuana use, including one involving domestic violence.

“Legalization in practice is a lot scarier than legalization in theory,” Sabet said. “It means a pot shop in your backyard, mass advertising and commercialization and greater health harms.”

In the book, Sabet takes on the myth that marijuana isn’t addictive. He said one in six kids who try marijuana will become addicted—the same as alcohol. That’s because young people are vulnerable than adults.

“There are more kids in treatment for marijuana today than all other drugs, including alcohol, combined,” Sabet said.

He worries that as other states and the District of Columbia consider legalization, more people will be hurt by the drug.