Adding to the ever-growing body of research that suggests legal access to marijuana may help mitigate the opioid crisis, a new study found that states with medical cannabis laws have seen a drop in opioid prescriptions for people aged 55 and younger.

Researchers from the University of Texas investigated prescription opioid use among people with private insurance (as opposed to those on publicly funded Medicare or Medicaid), and compared those rates in states with and without medical marijuana.

“When results were examined within each individual age cohort, opioid prescription rate varied depending on the stringency of state cannabis laws,” the study states. “In particular, in states which implemented medical cannabis use laws (but not other categories of cannabis liberalization laws), lower rates of opioid prescription were seen in the younger age cohorts (18–25, 26–35, 36–45 and 46–54 years).”

The findings were published last week in the journal Preventive Medicine.

Building on previous studies—including one that found opioid-related overdose deaths fell in states with legal marijuana dispensaries—the researchers used information from the database of one of the largest private health insurance providers in the country. This was important, the study’s authors write, because this subset of people “may exhibit different behaviors from Medicare and Medicaid subpopulations with regards to cannabis use.”

Past research has shown states with medical marijuana laws have issued fewer opioid prescriptions to people with government-funded health coverage.

The study population spanned more than four million individuals, which researchers broke down by age group in their analysis.

In 2016, when the research was being conducted, five states had fully legalized marijuana, 21 states had approved only medical cannabis and four other states had simply decriminalized possession. At the time, 1,770,081 people were enrolled in private insurance in states with legal medical marijuana access.

According to the study’s results, the states with the lowest prescription rates were those that had approved access to medical marijuana. When the results were examined by age group, researchers found that these lower rates were only seen in people ages 18 to 54.

“Overall, age-stratified adjusted analysis showed lowest rate of opioid prescription in states that allowed for medical cannabis use.”

While the authors admit there may be “a public health benefit associated with medical cannabis laws,” they point out this decrease in opioid prescriptions may also have to do with the fact that many states have implemented monitoring programs and other legislation designed to restrict access to opioids.

But, as the study states, “These findings suggest a difference between the privately insured versus Medicaid or Medicare insured populations, especially those who are older adults. Research has shown that Medicaid and Medicare beneficiaries generally have greater disability than those with commercial insurance, perhaps because a proportion of beneficiaries qualify for Medicare coverage based on a disability.” As a result, it’s possible that more patients with public insurance have been prescribed opioids compared to the privately insured.

Also, as the authors note, it’s not surprising that older people have more prescriptions—that just comes with age. They do wonder, however, if “these patients are more likely to use cannabis as an adjunct therapeutic agent for pain control.”

“Baby Boomers, who are now in their mid- 50s and 60s, represent demographic cohort who experienced illicit drug use, including cannabis, as a societal norm, resulting from societal pressures and stresses in their youth,” the study states. “While younger adults appear to use cannabis with greater frequency than older adults (aged 50 and above), studies reveal that cannabis use among older adults may be increasing.”

In fact, one recent study found that 3 percent of adults 65 and older reported using cannabis in the past year. That’s seven times the rate of Baby Boomers who reported use a decade ago.