In a new study, researchers led by Dr. Alex Crosby of the CDC's National Center for Injury Prevention and Control looked at the cases of suicide reported in 17 states in 2005 and 2006. They found that of those suicide victims tested whose blood alcohol levels were tested after their death, nearly a quarter had levels above the legal limit for driving a car.
They reported their findings in the June 19 issue of Morbidity & Mortality Weekly Report.
The percentage of suicides with high blood alcohol levels was greatest among American Indian/Alaska Natives at 37 percent, followed by 29 percent for Hispanics -- findings that hold implications for culturally specific intervention programs, Crosby said.
"Alcohol is connected to suicides across all [racial and ethnic] groups," he said. "When programs try to address suicide prevention, they should definitely include alcohol as one component."
Alcohol has long been a known risk factor in suicide, said Dr. Eric Caine, chair of psychiatry at the University of Rochester Medical Center in Rochester, N.Y.
But the study is unique because it examines the role of alcohol in suicides across all ethnic groups -- data that has been limited in prior studies, Crosby said.
"This is a really important paper because it underscores how much a common risk factor such as drinking contributes to something like suicide," Caine said. "Here's more data on how something like alcohol is fuel on the fire, and we need to ask ourselves what we are going to do about it."
To examine the relationship between alcohol and suicide among racial and ethnic groups, the researchers looked at data from the National Violent Death Reporting System from 2005 through 2006.
There were a total of 18,994 suicides in the 17 states that contributed to the database, and about 70 percent of those who committed suicide had been tested for alcohol.
Among those, the overall prevalence of alcohol intoxication was about 24 percent, and the highest percentage occurred among American Indian/Alaska natives, then Hispanics, and among patients of all ethnic groups between 20 and 49 years old (28 percent).
Alaska Natives/American Indians who committed suicide had the highest percentage of alcohol dependence and blood alcohol levels above 0.08 g/dL.
Also, researchers found a significantly higher percentage of men with blood alcohol concentrations above 0.08 g/dL than women in all populations, except among Alaska Natives/American Indians.
The results indicate that "many populations can benefit from comprehensive and culturally appropriate suicide prevention strategies," Crosby said.
He said there are few interventions that target minorities, although such programs are increasing.
"This is an invitation for public health approaches," Caine said. Since drinking considered ordinary behavior, one of the major challenges is taking something that's so common and building a prevention program around it, he said.
He noted that the authors highlight two approaches -- alcohol taxes and stricter blood alcohol content regulations for driving.
"We don't necessarily think of those measures as suicide prevention measures, but on the other hand, they may well be," Caine said. "These are broad social policies, but this study underscores how they can be tied to something like suicide. We have to think about that."
Some of the mechanisms linking alcohol to suicide include its effects on the nervous system and behavior, the researchers said.
"It can increase impulsivity, impair judgment, can have a dis-inhibitor effect on people," Dr. Crosby said. "It can increase feelings of hopelessness and depression."
"If you're depressed it makes your depression worse," Dr. Caine said, "and if you're not depressed you may become depressed."