While it’s often said that 20% to 30% of all opioid overdose deaths are intentional, a new study suggests that may not be the case. 

Instead, Columbia University researchers found that only about 4% of opioid overdose deaths can be attributed to suicide. Their findings were published Tuesday in JAMA.

For the study, researchers analyzed national data on opioid overdose deaths between 2000 and 2017. During that period, the percentage of opioid deaths attributable to suicide actually decreased, falling from 9% to 4%.

“It gives you a very different picture of the role of opioids in the suicide epidemic,” Dr. Mark Olfson, lead author and Columbia University psychiatry professor, told CNN.

However, the findings don’t necessarily mean opioid use and suicide risk are unrelated; they only suggest that a proportionally smaller number of people than previously believed are taking opioids specifically to commit suicide. 

But still, rates of both lethal opioid overdoses and suicides have spiked since 2000.

And despite the proportional decrease, the absolute number of intentional opioid overdose deaths has also increased. 

In 2000, the researchers found 0.27 opioid-related suicides per 100,000 people. In 2017, that rate more than doubled, increasing to 0.58 opioid-related suicides per 100,000 people.

Additionally, the study does not look into non-opioid suicide rates by those with opioid use disorder (OUD). Many behavioral health providers anecdotally report that people with OUD may choose to commit suicide when going through withdraw — but those suicide don’t always include opioids. 

As such, more research is needed to better understand how suicidal intent plays into opioid overdoses and vice versa, according to the researchers. 

“Considering the high risk of suicide after nonfatal opioid overdose, this information could be especially valuable in suicide prevention efforts,” Olfson said in a press release announcing the news.