“Our goal was to highlight the fact that these adverse outcomes likely go together, and effective efforts to help those with pain will likely need to simultaneously consider both overdose and suicide risk,” Ilgen said.

Bohnert and Ilgen point out that suicide notes are found in only about one-third of overdose deaths, making the motivations behind other overdose deaths less clear. That’s why grouping overdoses and known suicides by overdose together makes sense, they say.

“Unlike other common causes of death, overdose and suicide deaths have increased over the last 15 years in the United States,” Bohnert says. “This pattern, along with overlap in the factors that increase risk for each, supports the idea that they are related problems and the increases are due to shared fundamental causes.”

Both researchers have previously studied these issues in depth, and potential ways to address them. Bohnert co-directs the U-M Program for Mental Health Innovation, Services and Outcomes and is an associate professor of psychiatry at the U-M Medical School.

Ilgen, who directs the U-M Addiction Treatment Services program and is an associate director of the U-M Addiction Center, is a professor of psychiatry. Both researchers also work for the VA Center for Clinical Management Research and are members of the U-M Institute for Healthcare Policy and Innovation and the U-M Injury Prevention Center.

Supply or demand?

The rise in overdose and suicide death rates over the past two decades paralleled the rise in opioid painkiller prescriptions — and, later, the rise in use of heroin and illegally manufactured fentanyl.

The researchers look at the competing theories of whether an increased supply of opioids from legal and illegal sources or an increased demand for them because of social and economic factors was more likely to blame.

Although the paper notes that evidence from Australia suggests the supply theory has more credible support for an increase in overdoses, it maintains that both theories have validity and deserve to be addressed through policy solutions.

Because of the common factors involved, researchers say, the U.S. may be able to reduce the death toll from both overdose and suicide through increased use of proven prevention and treatment strategies.

Who’s most at risk

For both suicide and unintentional overdose, men had death rates twice as high as women in 2017, according to the researchers’ analysis of CDC data.

Rates of suicide deaths were highest for white men and American Indian/Alaska Native men, and they were lower across the board for women.

When it came to unintentional overdoses, white men younger than 40 had the highest rate, with nearly 50 deaths per 100,000. But the rate among black men rose in middle and older age, surpassing those of white and Native American men.

For women, unintentional overdose death rates were much higher than suicide rates among white, black and Native American women under age 65.

But Bohnert and Ilgen cite research on racial biases among medical examiners in ruling deaths as suicides or overdoses. They also note studies about the increased risk of suicide and overdose among people with mental health conditions and substance use disorders.

Proven treatments identified

People with chronic pain are at clear elevated risk for both unintentional overdose and suicide — a connection that hospitals and providers might not properly acknowledge.

“To date, many system-level approaches to address overdose and suicide have addressed these as if they are unrelated outcomes,” Ilgen says. “Our goal was to highlight the fact that these adverse outcomes likely go together, and effective efforts to help those with pain will likely need to simultaneously consider both overdose and suicide risk.”

To bring down the risk of suicide or overdose among those most at risk of dying from these causes, Bohnert and Ilgen lay out an array of potential interventions based on the evidence available from recent research.

For instance, they call for people who are on high-dose regimens of prescription opioids, or who are showing signs of prescription opioid misuse, to receive care that could reduce their suicide and overdose risk — which includes a slow, patient-centered tapering of their opioid use.

Reducing prescription opioid doses gradually may actually reduce patients’ pain, research has shown, and reducing the amount of opioid painkillers prescribed at any time could also help keep at-risk patients from having the means for suicide or unintentional overdose on hand.

The U-M team also notes that naloxone, which can reverse an opioid overdose —whether intentional or not — should be prioritized for the friends and family of such patients.

The researchers also call for greater availability of medication-assisted treatment for anyone with an opioid use disorder.

This could involve the use of methadone, buprenorphine or naltrexone, depending on the person and the availability of treatment, offered in concert with counseling around overdose and suicide prevention, treatment for any mental health conditions and naloxone distribution.

“Medication-assisted treatment for opioid use disorders has been repeatedly proven to reduce overdose deaths relative to no treatment or nonmedication treatment,” Bohnert says.

“Reducing the severity of opioid use disorder through medications will also improve mental health. Reducing barriers to use of these medications is essential to addressing both overdose and suicide.”