A large new study confirms what mental health experts and those who research firearms have known for some time: Owning a handgun vastly increases one’s risk of suicide.
The research, published Wednesday in the New England Journal of Medicine, goes beyond what smaller past studies have shown, however, by capturing suicide risk down to the individual level.
“This is really a groundbreaking paper,” said Michael Siegel, a public health researcher at the Boston University School of Public Health, who was not involved in the study.
Stanford University researchers tracked more than 26 million men and women in California who were 21 and older and who hadn’t owned guns before October 2004. A little under 3% of the cohort, or 676,425 people, became gun owners between then and 2016. The risk of suicide in this group was higher — around nine times so — than among non-owners. Those who died by suicide using a firearm — 6,691 people out of 17,894 total suicides — tended to be male, white, and of middle age (mean age of 41 years).
Those findings fall in line with past research on gun ownership and suicide risk. Previous studies have drawn conclusions by correlating city- or state-level data on firearm ownership and suicide rates, Siegel explained, but this study shows “individual risk increases [with gun ownership], not just the risk at the population level.” The size of the study, too, gives it more weight.
“This is a huge population and represents, so it’s one of the largest studies — probably the largest study — that’s been done,” Siegel said. “The sheer sample size of the study makes it absolutely unique. For that reason, I think the findings are unassailable [and] as definitive as you can possibly be in terms of the research.”
To arrive at their findings, the study authors linked data on handgun transfers (which include purchases from licensed firearms dealers) with data from the state’s voter registration database, which has up-to-date information on whether voters are alive or dead. Starting in October 2004, the authors retrospectively followed the 26 million individuals included in their cohort through December 2016.
“We know so little about firearms owners since there’s no way of tracking that on a national level,” said Claire Houtsma, a doctoral candidate in clinical psychology at the University of Southern Mississippi, who researches access to firearms and was not involved in the study. “It’s such a complex issue and people don’t want their firearms tracked, so just the fact that they have this [information] is interesting.”
The study also found that among males, gun owners had an eight times higher suicide risk than non-owners. Among female gun owners, that risk was more than 35 times higher.
As for what could explain these sharp differences, “women attempt suicide more often than men,” said David Studdert, a Stanford health policy researcher and lead author of the study. However, women tend to use methods that are much less lethal than the methods that men use, he said. But “When you combine [that] high propensity to attempt [suicide] with a very lethal means — and familiarity or access to that mean — that may drive that rate for women way up.”
Further patterns emerged when Studdert and his team investigated what happened right as people bought guns. Among those who purchased one, “the risk is immediately high in the weeks following the purchase,” he said.
Of the 1,200 owners who died by suicide using a handgun over the study period, roughly 1 in 7 suicides occurred within the first month of buying it — which included the 10-day waiting period mandated by California law when purchasing a gun. “And that shows that some people have intentions to die by suicide when purchasing a gun,” Studdert said.
However, the vast majority of suicides by firearm among gun owners happened a year or more after purchasing the weapon. “It provides support for extreme risk protection orders, or ‘red flag’ laws,” said Siegel. These laws allow a family member or law enforcement official to petition a judge to temporarily take away guns from someone who exhibits suicidal ideations or seems to present a danger to others. “Research shows that this does save lives,” Siegel said.
Still, the findings only represent one state, and may not be entirely generalizable. “California is one of the states with the most restrictive firearm laws,” said Houtsma. Those wishing to purchase a gun are only allowed to do so from a licensed dealer, and have to wait 10 days before they get the firearm. “I would guess that other states [with looser laws] have even larger magnitudes of findings,” she said.
Studdert, who shared that this was the first analysis to come out of a five-year study that aims to analyze the secondhand effects of having guns at home, said that the team’s next goal is to look at homicide and accidental deaths to see the combined effect of these deaths and suicides on a household level.
Another future step might also be a state-by-state comparison, Siegel said.
“It would be tremendously valuable to have similar studies done across multiple states to be able to compare whether or not there are differences based on state firearm laws,” he said.
If you or someone you know is considering suicide, contact the National Suicide Prevention Lifeline at 1-800-273-8255 (Español: 1-888-628-9454; deaf and hard of hearing: 1-800-799-4889) or the Crisis Text Line by texting HOME to 741741.