A large-scale study has found that nearly a quarter of U.S. suicide victims are legally intoxicated when they die.  These victims are also much more likely than their sober counterparts to commit suicide by violent means such as using a firearm, hanging themselves or falling to their deaths.

Researchers at Portland State University analyzed the blood-alcohol levels in nearly 58,000 suicide cases across 16 states and found that 22 percent of victims were drunk when they died.

Twenty-four percent of men and 17 percent of women who committed suicide had blood-alcohol levels of at least 0.08 g/dL, the legal standard for intoxication.

“This is the largest study to date in the U.S. that looked at blood alcohol levels at the time of death,” lead researcher Dr. Mark Kaplan, professor of community health at Portland State University, told FoxNews.com.  “Most studies in the past have focused on the risk of suicide among people with chronic alcohol problems like alcoholism or alcohol dependence.”

In the current study, Kaplan and his team found than less than half of the victims had a problem with alcohol dependence or alcoholism or a history of prior suicide-related behaviors, such as attempts or ideation – though 76 percent did show prior evidence of mental health problems.

“One hypothesis is these were individuals responding to major life stressors or crises, who engaged in drinking with a firearm present within a few hours of taking their lives and became disinhibited by the alcohol,” Kaplan said.  “They were drinking excessively in order to make it possible to die by suicide.”

The rates of committing suicide while intoxicated were highest among young men, American Indians/Alaska Natives, veterans and those from rural areas or low education levels.

“When you look at men who die by suicide across the age span, there is a dramatic reduction in the likelihood of intoxication among older men,” Kaplan said.  “For younger men, the act of dying by suicide may be more impulsive, and alcohol might facilitate the completion of that suicide.  We’re more likely to see young men taking their lives in the presence of life crises such as financial problems, criminal justice problems or problems with an intimate partner.”

“In older age, it’s a more planned outcome,” he added.  “Older men are more likely to take their lives in the presence or chronic health problems.

While women are much less likely to die by suicide than men, Kaplan said it was nevertheless ‘surprising’ to see how many women committed suicide while intoxicated.

“When you look at suicide, the rates are almost four times higher for men than women, so you would expect the rates of intoxication among women would be lower as well, but in some groups they were nearly equal,” Kaplan said.

Meanwhile, among ethnic groups, the rates were nearly twice as high for American Indians and Alaska Natives as they were for other groups: 41 percent of American Indian or Alaska Native men and 33 percent of women committed suicide while intoxicated.

“American Indian and Alaska Native populations historically have had the highest suicide rates as well as high rates alcohol-related problems,” Kaplan said.  “Perhaps it’s because they have greater access to alcohol.  That’s the next thing we want to look at: What role does easy access to alcohol play in the likelihood of committing suicide?”

Suicide is the 10th leading cause of death in the U.S., making it a major public health problem, according to Kaplan.  He said this study points to the need for government and state programs aimed at lowering suicide rates and developing targeted prevention strategies designed for groups identified at high risk of alcohol-associated suicide.

The study was published online Thursday in BMJ’s Injury Prevention.  It was funded with a grant from the National Institute on Alcohol Abuse and Alcoholism, a branch of the National Institutes of Health.