The study is the first to compare alcohol use among those who committed suicide with that of a nationally representative survey of non-suicidal adults in the United States. Its purpose was to provide estimates of the relative risk of suicide associated with drinking and heavy drinking occasions.
The report was published online June 12 by the Annals of Epidemiology.
The researchers found that alcohol was detected in nearly 36 percent of men and 28 percent of women who committed suicide. Additionally, a blood alcohol content at or above .08 grams per deciliter — considered legally intoxicated in many states — was a potent risk factor for suicide across the age spectrum, and that people who committed suicide were four to 20 times more likely than others to have engaged in heavy drinking at any point in their lives. High levels of alcohol consumption were also associated with the methods of suicide that are most likely to be fatal, such as shooting and hanging.
"The key finding is that the data showed alcohol misuse is common among people who are suicidal," said Kaplan, a faculty member at the UCLA Luskin School of Public Affairs. "Those who drank, drank heavily in the hour before taking their lives. Fewer than half of those who were alcohol positive at the time of death had a history of alcohol-related problems."
The researchers also found relative gender parity among people who committed suicide with elevated blood alcohol levels — a surprising finding because men in general are more likely than women to drink and drink in excess. The report noted that one possible explanation is that women are more likely than men to commit suicide by poisoning themselves, and alcohol may be used as one of the poisoning agents in combination with other substances.
A particularly troubling finding was that nearly a quarter of all those who committed suicide under the age of 21 tested positive for alcohol at the time of death.
The report puts forth several recommendations for health professionals and policy makers, in particular for addressing the connection between heavy drinking and suicide among the underage population, including:
In addition, Kaplan said, the findings should prompt suicide prevention workers to probe for alcohol intoxication when dealing with people who are suicidal.
The researchers used data from the National Violent Death Reporting System to identify those who had used alcohol or showed signs of intoxication before they committed suicide between 2003 and 2011. Population estimates of comparable use of alcohol were based on the National Epidemiologic Survey on Alcohol and Related Conditions.
Other authors were Nathalie Huguet of Portland State University, Bentson McFarland of Oregon Health and Science University, Raul Caetano of the University of Texas School of Public Health, Kenneth Conner of the University of Rochester Medical Center, Norman Giesbrecht of the Centre for Addiction and Mental Health, and Kurt Nolte of the University of New Mexico School of Medicine. The study was supported by the National Institute on Alcohol Abuse and Alcoholism (R01 AA020063).