Medical Marijuana Laws Increase Risk for Cannabis Use Disorders

Residents of states where medical marijuana is legal have an increased risk of engaging in illicit cannabis use or developing marijuana addiction, according to a report by Columbia University.

The study, published in JAMA Psychiatry, collected national survey data from 1991–1992, 2001–2002 and 2012–2013. Researchers examined cannabis use among nearly 118,500 people in 39 states.

Overall, from 1991–1992 to 2012–2013, illicit marijuana use and cannabis use disorders increased more in states that passed medical marijuana laws than in those that had not.

“Medical marijuana laws may benefit some with medical problems,” lead author Deborah Hasin said in a statement. “However, changing state laws […] may also have adverse public health consequences, including cannabis use disorders.”

Researchers found that illicit marijuana use decreased and cannabis addiction changed little among participants from 1991–1992 to 2001–2002. But illicit use and addiction increased from 2001–2002 to 2012–2013.

The predicted prevalence of cannabis use and disorder were higher in California than in other states that had medical marijuana laws in 1991–1992. Between 1991–1992 and 2012–2013, states with medical marijuana laws, excluding California, experienced a slight increase in the prevalence of cannabis use and addiction.

In the study, researchers concluded that medical marijuana laws seem to have increased the prevalence of illicit marijuana use and cannabis addiction. They said that statewide policy changes could have affected these outcomes.

“Policy and clinical professionals should recognize that cannabis disorders can be severe, treatment needs are increasing, and treatment can be effective,” the authors wrote.

Marijuana Laws Have Not Affected Colorado Teens, Per Report

The JAMA Psychiatry study found that medical marijuana laws affected illicit use in multiple states. But a report published in JAMA Pediatrics indicated that recreational cannabis legalization did not affect the number of Colorado teens who used the drug.

The study examined teen marijuana use among 253,902 adolescents in 47 states. The results showed that marijuana use among eighth- and 10th-grade students in Washington increased between 2010–2012 and 2013–2015.

However, cannabis legalization did not affect Colorado teens. Researchers found no differences in perceived harm or past-month cannabis use among eighth- and 10th-graders after the state legalized recreational marijuana.

Magdalena Cerdá, lead author of the study, told The Denver Post that marijuana exposure from an existing medical cannabis industry in Colorado could be the reason the recreational laws affected fewer teens in the state.

The cannabis industry in Washington wasn’t as refined as Colorado’s upon recreational marijuana legalization. Cerdá suggested that less exposure to cannabis advertising prior to legalization may have caused more Washington teens to try the drug after the state approved recreational use.

Cannabis Use Disorder on the Rise

In a 2016 study led by Hasin and published in the American Journal of Psychiatry, researchers found that the number of people using marijuana over a one-year span more than doubled from 2002 to 2013. During that time, more Americans developed cannabis use disorders.

The study used federal data to examine alcohol use, drug use and mental health conditions among more than 36,000 adults. The results indicated that nearly 6 million adults in the United States experienced marijuana addiction in the past year. More than one in six adults developed the condition at some point during their lives.

Hasin said that three out of 10 cannabis users dealt with marijuana abuse or dependence in 2012 and 2013. However, just 7 percent of people diagnosed with marijuana addiction in the past year received cannabis-specific treatment.

Medical Disclaimer: aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.

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