A recent study finds that adults are more inclined to take illegal drugs where medical marijuana is legal. The study was published Wednesday in the Journal of the American Medical Association (JAMA) Psychiatry.

The study found that adults are at an increased risk of cannabis use in the states that adopted the legal use of medical marijuana, as reported by Reuters. The risks of medical marijuana law are important to announce, according to the lead author of the study, Deborah Hasin from the Mailman School of Public Health at the Columbia University in New York.

"Just as the case for alcohol, not everybody who uses it is harmed," Hasin said. "The laws may not be too relevant and salient to teenagers so we thought it was important to look at adults."

The study concludes three national studies conducted within 22 years, from 1991 to 2013. Those studies analyzed the illegal drug use and compare it with the rates of cannabis use disorder between the states with the legal marijuana and the ones without it.

Researchers found that illegal drug use in the states without marijuana legalization increase 2.16 percent in 22 years, from 4.54 percent to 6.70 percent. While the increase of illegal drug use in the states that legalized marijuana is 3.6 percent, from 5.55 percent in 1992 to 9.15 percent in 2013.

In 15 states that have legalized medical marijuana, California and Colorado showed the highest increase of illegal abuse of marijuana, as reported by Washington Times. The other states that have medical marijuana laws are Arizona, Connecticut, Maine, Maryland, Massachusetts, Michigan, Montana, Nevada, New Jersey, New Mexico, Vermont, Oregon and Washington.

The researchers concluded that people, who live in the states where medical marijuana laws are applied, do not see the marijuana as a harmless substance. That is the main reason for  the increase of the marijuana abuse. Watch the report in that review the real effect of legalized marijuana in Colorado below: