Medical marijuana sales also reportedly increased over 2016, but not at the levels the recreational industry is enjoying.
That's the basic conclusion of a study published today that has reignited the debate over whether marijuana laws encourage illegal use of cannabis.
Reaction was swift from those who support marijuana legalization laws.
California passed the first medical cannabis law in 1996. The average rate went from 1.35 percent in 1991-1992 to 2.30 percent in 2012-2013 in states that didn't enact medical marijuana laws, and from 1.48 percent to 3.10 percent in states that did.
Illicit use was generally defined as illegal use of marijuana without a prescription at least 12 times during the past year.
The first was 1991-1992, when marijuana was not legal in any state.
By 2012, more than one-third lived in states with medical marijuana laws, and fewer viewed cannabis use as risky.
Tennessee teacher planned to take 15-year-old girl to Mexico
The pair's disappearance generated more than 1,500 tips, a sighting in Oklahoma City and Amber alerts in Tennessee and Alabama. Elizabeth was missing for more than a month after she was allegedly kidnapped by her former teacher, 50 year-old Tad Cummins.
The researchers analyzed responses to national surveys from almost 120,000 adults from 39 states.
To investigate, the authors of the new study consulted data from three studies: the 1991-1992 National Longitudinal Alcohol Epidemiologic Survey, the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions and the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III.
The report said wholesale weed prices were down 33 percent overall, so Colorado customers could be using the reduced-priced pot as a means to stock up.
Previous research that focused on adolescents' use of the drug in the wake of medical marijuana laws didn't find an increase in that age group, she said.
The increase in illicit marijuana use and marijuana use disorders were 1.4 percent and 0.7 percent higher, respectively, in states that had legalized medical marijuana, compared with states that had no MMLs.
Post-traumatic stress sufferers may soon qualify for medical pot in Colorado. Again, a higher rate and a bigger percentage increase. This is not like alcohol, which is also readily available to and a significant problem for youth, because alcohol use does not cause the same type of permanent changes to teens' ability to concentrate and learn that marijuana does.
The study didn't account for differences in state policy, other than by separating Colorado and California from the other states.
Most recent research has concluded that marijuana legalization laws do not prompt an increase in use of the drug by teens. This leaves tourists with nowhere to consume the plant and given the fact Nevada hosts one of the country's favorite tourist destinations, Las Vegas, it is wise to think about this accommodation.
Eight of those states plus the district have also legalized the drug for recreational use. Thus, identifying factors underlying increased adult illicit use is important.