(CNN) As more states consider passing "red-flag" laws that would let authorities temporarily seize guns from people deemed a risk to themselves or society, a new study suggests the laws might have prevented some firearms-related suicides.

The University of Indianapolis study focuses on the two states that have had red-flag laws the longest: Indiana (since 2005) and Connecticut (since 1999).

The study, published in the June 2018 issue of Pyschiatric Services , found that Indiana's gun-related suicide rate was 7.5% lower in the 10 years after the law was enacted (2005-2015), compared to what would have been expected without the law.

More than 5,100 people killed themselves with a firearm in Indiana during those 10 years after the law took effect. But the statistical analysis shows the law may have prevented an additional 383 suicides by gun, according to the study, led by Aaron Kivisto, an assistant professor of clinical psychology.

A 13.7% drop in Connecticut

Connecticut also demonstrated a drop, especially after 2007, when Connecticut authorities stepped up enforcement of the law following a mass shooting at Virginia Tech that year, the study says.

The study found Connecticut's gun-related suicide rate dropped 1.6% in the first few years after its law passed in 1999, relative to what would have been expected without it.

But the drop was more pronounced -- 13.7% -- from 2007, when Connecticut authorities started using the law more often -- to 2015.

What red-flag laws do

Connecticut and Indiana were the first states to enact red-flag gun laws , also known as extreme-risk protection order laws or gun violence restraining order laws.

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A few other states have passed them since then -- including Florida and Rhode Island this year -- and more are considering them, spurred in part by mass shootings like the one that killed 17 at Florida's Marjory Stoneman Douglas High School in February

The laws differ state to state, but they generally allow specific people -- law enforcement officers and, in some states, relatives of the person in question -- to ask a judge to temporarily prohibit someone from possessing or buying firearms

This would be based not primarily on criminal history or mental health disqualifications already enshrined in law, but rather over allegations that the person is likely to harm themselves or others.

The laws have drawn criticism from a range of observers, including gun-rights proponents and the Rhode Island chapter of the American Civil Liberties Union.

"This is very dangerous for all our rights, as it moves us to a 'Minority Report' type of society, where one can lose their rights for what they 'might do' in the future," said the Gun Owners of America firearms lobbying group in a statement

But supporters say such laws fill a gap. While other laws prohibit gun ownership for previously adjudicated crimes or mental health dispositions, red-flag gun laws can let authorities confiscate guns before a crime or suicide is attempted, when evidence shows danger is imminent.

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Connecticut passed its law after a shooting at the state lottery headquarters. Indiana passed one after a police officer was shot and killed in Indianapolis.

While mass shootings seem to spur legislatures to pass red-flag laws, in practice they've functioned as a suicide prevention mechanism, Kivisto told CNN.

Kvisito points to research showing that in some years, more than 80% of the red-flag gun seizures in Indianapolis happened because of perceived risks of suicide rather than fears of homicide, domestic violence or psychosis, Kivisto said.

Crunching the numbers

You might wonder how the authors estimated what might have been expected without the laws. The answer: They compared Indiana and Connecticut to an amalgamation of states that were similar in key categories, such as demographics, alcohol consumption, employment rate and gun ownership rate.

So, Indiana was compared to a group of states with similar statistics. From 1981 to 2004, Indiana's firearm suicide rate (7.3 per 100,000 people) equaled that of the comparison states. But after Indiana enacted its law in 2005, the firearm suicide rate dropped to 6.98 -- 7.5% lower than the 7.55 shown by the other states.

There's mixed evidence on whether the laws are linked to a reduction in suicides by any means.

In Indiana, suicides decreased overall when the law was implemented, driven by the reduction in suicides by firearms, Kivisto said.

But in Connecticut, nonfirearm suicides rose when the law was enforced post-Virginia Tech. The reduction in suicides by guns and the increase in suicides by other means were "almost a wash," Kivisto said.

There's been no published research on whether red-flag laws have had effects on homicide rates. "Certainly more research is needed," the Indianapolis professor said.