A new study by Stanford University researchers found that handgun owners are nine times more likely to die by suicide than non-gun owners. The study, published in the New England Journal of Medicine this month, confirms what mental health experts have known for decades — that there is a positive correlation between firearm ownership and suicide risk.

The findings are particularly relevant as many Americans have become new handgun owners since the beginning of the COVID-19 pandemic. Industry data show retailers sold 2.5 million firearms in March, an 85% increase over the same period last year. That increase could bring serious consequences, as psychologists and other experts have raised the possibility of an approaching mental health crisis.

Matthew Wintersteen, director of research in the division of child and adolescent psychiatry at Thomas Jefferson University, noted that after the 1918 influenza pandemic, studies showed that suicides increased.

“The concern is, do more people who could be facing a number of other challenges that could increase anxiety, depression, and relationship issues have more access to firearms?” Wintersteen said. “As things settle a little bit, we’re looking for any emergence of these issues.”

Prior to the Stanford study, researchers didn’t know how much gun ownership increased risk of suicide, he said.

“This is probably one of the most rigorous scientific studies on this topic from a scientific standpoint,” said Wintersteen, who was not involved with the study. “The only surprising finding from it for me was the magnitude of suicide risk that they found. We didn’t know it was that much greater.”

In the new study, researchers tracked more than 26 million registered voters in California who were age 21 and older and hadn’t owned guns before October 2004 over a 12-year period. Out of that group, 676,425 — a little under 3% — became gun owners during the study period. Their suicide risk increased significantly, especially right after purchasing the gun, and remained elevated over the course of the study. Male gun owners had an eight times higher suicide risk than male non-owners, and female gun owners were 35 times more likely to die by suicide than female non-owners.

David Studdert, a law professor at Stanford University who specializes in health policy and the lead author of the study, said that the difference in risk between male and female gun owners can be partially attributed to the fact that women attempt suicide more often than men, although they typically use methods that are less lethal.

“When you take that high attempt rate and pair it with a very lethal method, like a gun, it might help explain that high risk,” he said.

Researchers also examined whether the gun owners studied had an increased risk of suicide from other known factors such as smoking, using intravenous drugs or drinking to excess. They found no association between gun ownership and those three causes of death.

“We were trying to understand not just how gun ownership is associated with higher rates of mortality, but also how that risk changes over time,” Studdert said. “Previous designs in this area didn’t have the ability to follow people longitudinally.”

While it would be difficult to replicate the study outside of California due to the fact that the state mandates legal handgun purchases be completed through a licensed dealer and recorded in a database by the Department of Justice, Studdert said that suicide risk might be higher in other states with less strict gun laws. But Wintersteen said that the message about suicide risk and gun ownership shouldn’t be, “Get rid of your guns.”

“In Pennsylvania, where gun ownership is high, particularly in rural communities and counties, nobody hears that message,” Wintersteen said. “The message needs to be, ‘Let’s limit access to prevent you, or your family members, from taking their lives.’ There are organizations, like Hold My Guns, that will keep your gun for you if you’re in crisis, so this doesn’t happen.”

People in crisis can call the National Suicide Prevention Lifeline at 800-273-TALK (-8255) or use the Crisis Text Line by texting TALK to 741741.