The Trump administration issued a warning Thursday about the dangerous effects of marijuana on adolescents and pregnant women.
The advisory comes after 33 states have legalized marijuana in some way, whether for recreational or medical use.
Adams said legalization of the drug in many states has normalized its use among adolescents.
"Over and over again I hear a great and rising concern about the rapid normalization of marijuana use and the impact that a false perception of its safety is having on our young people and on pregnant women," Adams said.
He said the concentration of THC in marijuana has tripled since the 1990s, making it more potent.
“The science tells us the higher the delivery, the higher the risk,” he said. "You can be addicted to marijuana."
While Adams said the risks of using marijuana are still not fully known, use among adolescents can affect brain development.
Health and Human Services Secretary Alex Azar said it's a priority of the Trump administration to eliminate barriers that prevent research into the risks and benefits of marijuana.
"We do believe more research needs to be done on marijuana," he said. "We want to open that up for more research, and that is a priority for this administration."
“This advisory is intended to raise awareness of the known and potential harms to developing brains, posed by the increasing availability of highly potent marijuana in multiple, concentrated forms,” the advisory reads.
In 2017, more than 9 million people aged 12 to 25 reported marijuana use in the past month.
Marijuana use among pregnant women is also becoming more frequent.
Between 2002 and 2017, the percentage of pregnant women using marijuana doubled from 3.4 percent to 7 percent.
Marijuana use during pregnancy can have negative effects on a developing fetus, including lowering birth weights.