Columbia researchers, analyzing national data on opioid overdose deaths, have found that only 4% of opioid-related overdose deaths are due to suicide—far below recent estimates of 20%-30%.

The findings were published today in JAMA.

"Our findings suggest that the current emphasis on the contribution of suicide to opioid-related deaths may be overstated and that for most individuals who overdose on opioids, the primary clinical focus should be on substance use," says the study's leader Mark Olfson, MD, MPH, the Elizabeth K. Dollard professor of Psychiatry, Medicine, and Law at Columbia University Vagelos College of Physicians and Surgeons.

The study is the first to use national data on opioid overdose deaths between 2000 and 2017 to find out what share of these deaths in individuals age 15 and older were unintentional, due to suicide, or of undetermined intent.

Over the 17-year study period, the percentage of opioid-related overdoses attributed to suicide decreased from 9% to 4%.

However, the rate of opioid-related suicide deaths more than doubled, from 0.27 to 0.58 per 100,000 people, and the rate of unintentional deaths increased over six-fold, from 2.20 to 13.21 per 100,000 people. (Although the percentage of overall opioid-related deaths that were undetermined in intent decreased from approximately 17% to 5%, their rate increased from 0.51 to .79 per 100,000.)

"It's likely that the increasing use of illicit fentanyl, which is approximately fifty times more potent than heroin, has contributed to the rapid increase in unintentional opioid overdose deaths," says Olfson.

Though the researchers did not find a close link between opioid overdose deaths and suicide deaths—two ongoing public health crises—they note that the increase in suicide deaths in the US may still be driven, at least in part, by the rise in opioid overdose deaths because of the absolute increase in opioid-related suicide deaths.

Additional research is needed to understand the role of suicidal intent in opioid overdoses, say the authors. "Considering the high risk of suicide after nonfatal opioid overdose, this information could be especially valuable in suicide prevention efforts," Olfson says.

"This type of rigorous research accessing large sets of data is essential to understanding and alleviating the social and clinical factors adversely affecting the health of our population," adds Jeffrey A. Lieberman, Chair of the Department of Psychiatry at Columbia University Vagelos College of Physicians and Surgeons.