Committee releases second report on marijuana health effects

The state’s Retail Marijuana Public Health Advisory Committee has released its second set of findings from the committee’s review of the scientific literature currently available on the health effects of marijuana use.
The report, “
Monitoring Health Concerns Related to Marijuana in Colorado: 2016,” also provides survey data about marijuana use in Colorado and data from hospitals and the poison center on potential marijuana-related health effects. Senate Bill 13-283 requires the committee to monitor the emerging science and medical information about marijuana use and report its findings.

“Just as with tobacco and alcohol, continued monitoring of marijuana use and potential health effects help guide our work to protect the health of Colorado’s citizens,” said Dr. Larry Wolk, executive director and chief medical officer at the Colorado Department of Public Health and Environment. “We want to base policy decisions and educational campaigns on sound science.”

The report recommends continued monitoring of several trends, including:

  • About 6 percent of pregnant women choose to use marijuana while pregnant. This percentage is higher among those with unintended pregnancies as well as younger mothers or those with less education. Using marijuana during pregnancy is associated with negative effects on exposed children, including decreased cognitive function and ability to maintain attention on task. Effects may not appear until adolescence.
  • At least 14,000 children in Colorado are at risk of accidentally eating marijuana products that are not safely stored, and at least 16,000 are at risk of being exposed to secondhand marijuana smoke in the home. The committee found strong evidence such accidental exposures can lead to significant clinical effects that, in some cases, require hospitalization.
  • More than 5 percent of high school students use marijuana daily or nearly daily. This has been the case since at least 2005. The report finds weekly marijuana use by adolescents is associated with impaired learning, memory, math and reading, for as long as 28 days after last use. Weekly use also is associated with failure to graduate from high school. In addition, adolescent marijuana users are more likely to develop cannabis use disorder or be addicted to alcohol, tobacco or illicit drugs in adulthood.
  • In Colorado, one in four adults ages 18-25 reported past-month marijuana use and one in eight use daily or nearly daily. These numbers have been consistent since marijuana’s legalization.

There are indications that policy and education efforts about the potential health effects of marijuana are working. For example, marijuana exposure calls to the Rocky Mountain Poison and Drug Center have decreased since 2015. This includes calls about accidental exposures in children under 9 years old. In addition, the overall rate of marijuana-related emergency department visits dropped 27 percent from 2014 to 2015. (2016 data is not available yet.)

The report also cited these trends:

  • Past-month marijuana use among adults and adolescents has not changed since legalization either in terms of the number of people using or the frequency of use.
  • Based on the most comprehensive data available, past-month marijuana use among Colorado adolescents is nearly identical to the national average.
  • Daily or near-daily use of marijuana among adults in Colorado is much lower than daily or near-daily use of alcohol or tobacco.

Based on its findings, the committee also recommends continuing to use survey, poison center and hospital data to monitor trends in marijuana use and health effects; state support of research to fill important gaps in public health knowledge; and continued public education about the potential risks of marijuana use.

The 14-member Retail Marijuana Public Health Advisory Committee includes physicians, scientists and public health officials. Committee members are experts in drug epidemiology, surveillance epidemiology, medical toxicology, pediatric medicine, psychiatry, drug addiction, pharmacology, pulmonary medicine, neonatal and perinatal medicine, and public health.