The findings, which appear in the July issue of the Journal of the American Board of Family Medicine, show that nearly 19 percent of the 38.6 million American adults with mental health disorders use prescription opioids, which are designed to relieve acute pain, compared with only 5 percent of those without.
Adults with depression and anxiety receive 51 percent of the 115 million opioid prescriptions distributed each year in the U.S., the study found.
The higher rate of use of opioids among those with the two most common types of mental illness in the country holds true across all levels of pain and across different types of pain, including that stemming from cancer and arthritis, the study found.
“Independent of pain and independent of medical conditions, having a mental health disorder is strongly associated with getting an opioid prescription, which is really, really concerning,” Dr. Brian Sites, the anesthesiologist, said in an interview in his office at Dartmouth-Hitchcock Medical Center last week.
The finding “suggests that there may be additional patient- and provider-related factors specific to those with mental illness that increase the likelihood of receiving prescription opioids,” the study authors wrote.
Being able to identify a subset of the population that might be more likely to use opioids regardless of their pain levels could help providers and policy makers address opioid use, the authors wrote.
Sites, who called the results “absolutely breathtaking,” said managing pain for patients he sees before, during and after surgery can be complicated when those patients have mental health disorders.
“I realize how complicated it is to deal with some of these issues from a pain standpoint for an operation,” said Sites, who had recently been in an operating room and was wearing scrubs during the interview. “I figure maybe there are issues kind of on a larger scale as well.”
He noted that the study is coming out in the midst of an opioid epidemic, which claimed the lives of 112 Vermonters and about 420 Granite Staters in 2016. Though only some of those overdoses were from prescription medications, previous studies have shown that some people begin using opioids through a prescription and then move on to illegal drugs, said Sites, who is also the associate dean of continuing medical education at Geisel School of Medicine.
Dr. Marc Larochelle, an internist at Boston Medical Center who sees a lot of patients with pain and addiction issues, said he did not find the results of the study to be shocking because the relationship between mental health issues and pain — which opioids are designed to treat — is well documented.
But, Larochelle, who was not involved in the study, said he did find it striking to see that this segment of the population is receiving more than half of the opioids providers prescribe. It’s a statistic he hadn’t seen before, he said.
The study “highlights a population that is worth looking at,” Larochelle said.
This is especially true because the country’s use of prescription opioids is concentrated among this population and because those with mental illness are known to have a higher risk of opioid-related harm, he said.
The research team, which was led by Matthew Davis, a University of Michigan researcher who earned his doctorate at Dartmouth College and a master’s in public health from Geisel School of Medicine, used the 2011 and 2013 data from the national Medical Expenditure Panel Survey (MEPS) to find the relationship between opioid use and the two most common mental health conditions affecting American adults — depression and anxiety.
The MEPS is a set of surveys of U.S. families and individuals, their medical providers and employers on the health services that patients use, how often they use them, the costs they incur and how they pay.
Researchers excluded those who were institutionalized during the study period, and were left with a sample of 51,891 adults. They identified those with mental health conditions based on self reports and clinical diagnoses. Similarly, opioid use was tracked through self reports and pharmacy data.
The new study’s authors acknowledge several limitations to their work.
It does not describe the relationship between mental health disorders and opioid use. The study did not direcly address whether having a mental health condition means someone is more likely to use opioids or whether using opioids might make people more likely to develop a mental health disorder.
This is a relationship that Larochelle described as being akin to the chicken and the egg.