- Alcoholics have a much higher rate of death by suicide than do members of the general population.
- Those alcoholics with a history of suicide attempts appear to have a significantly more severe course of alcohol dependence than other alcoholics.
- The fathers, mothers and siblings of alcoholics who had attempted suicide also showed a significantly higher prevalence of suicide attempts.
Contemplating suicide is very common, according to a 1997 article in the New England Journal of Medicine. In fact, up to one third of the general population has thought about suicide at some point in their lives.
The strongest predictor of suicide is psychiatric illness; more than 90 percent of people who commit suicide have diagnosable psychiatric illnesses at the time of death, usually depression, alcohol abuse, or both. The lifetime risk for suicide completion among alcohol-dependent individuals has been reported to be almost 10 percent, which is five to 10 times greater than that found among the general population. A study in the April issue of Alcoholism: Clinical & Experimental Research seeks to identify risk factors for suicide attempts among a large family-based sample of alcoholics from the Collaborative Study on the Genetics of Alcoholism (COGA).
"We found that alcohol-dependent individuals with a history of suicide attempts had a significantly more severe course of alcohol dependence," said Marc A. Schuckit, principal COGA investigator at the University of California San Diego site, also of the Veterans Affairs Medical Center, and corresponding author for the study. "They also had a higher prevalence of both independent and substance-induced psychiatric disorders, as well as other substance dependence." Schuckit speculated that increased alcohol intake by this subgroup of alcoholics may have led to more severe problems, which may have then resulted in brain dysfunction, neuropsychological changes and subsequent judgment impairment, an increased likelihood of mood swings, and alcohol-related violent behavior. All of these factors could have contributed to life problems, as well as suicide attempts.
For this COGA investigation, 3,190 alcoholic men and women were given semi-structured, detailed interviews. Information about suicidal behavior, socioeconomic characteristics, psychiatric comorbidity, substance-use disorders and characteristics of alcohol dependence were obtained from the alcohol-dependent probands (original subjects of the study), their relatives, and controls (families without a history of alcohol dependence).
Of the total number of alcoholics, 522, or more than 16 percent, had a history of ever having attempted suicide, whereas 2,668, or close to 84 percent, did not. First-degree relatives (fathers, mothers and siblings) of individuals who had attempted suicide also showed a significantly higher prevalence of suicide attempts than other alcoholics, but - according to previous research - no enhanced rate of alcohol dependence, psychiatric comorbidity, or other substance-use disorder. This suggests that suicidal behavior may be transmitted in families independent of alcohol dependence, psychiatric disorders, or other substance-use disorders.
"Is there a suicide gene? Probably not," said Robert M. Anthenelli, associate professor of psychiatry in the College of Medicine at the University of Cincinnati, and director of substance dependence programs at the Cincinnati Veterans Affairs Medical Center, "but that's beyond the scope of this paper's findings. What this finding does is give some support for the idea that 'suicidality' or suicide attempts seem to run in families. However, family studies rarely do a good job of teasing out nature versus nurture, or genetics versus environment. What this study does nicely is show that a suicidal 'trait' seems to exist independent of substance-abuse disorders as well as other psychiatric disorders."
Anthenelli added that the size of the study makes the associations found between suicidality and alcohol dependence more meaningful and believable than similar findings in previous, smaller studies. "Another strength is the percentage of women included, almost 40 percent," he said, "which a lot of other studies are not always able to achieve." In fact, he said, some of the gender differences in the findings were notable.
"The odds ratio of alcoholic women making a suicidal attempt was 2.86," he said. "This means that an alcoholic woman has almost a three-fold greater likelihood of attempting suicide than a male alcoholic. That's powerful. It also fits well with the knowledge that women in the general population make more suicide attempts than men, even though men have a higher completion rate."
Schuckit plans to continue with the investigation of suicidality among alcoholics in order to better understand and prevent suicide attempts and completions among this subgroup. "The underlying theme of this paper," said Schuckit, "and of the COGA studies in general, is that alcohol-dependent individuals who drink will likely have mood problems. Those that drink a lot will have major problems."
Co-authors of the Alcoholism: Clinical & Experimental Research paper included: U.W. Preuss, T.L. Smith, G.P. Danko, K. Buckman, L. Bierut, K.K. Bucholz, M.N. Hesselbrock, V.M. Hesselbrock, and T. Reich of the University of California San Diego, and the Veterans Affairs Medical Center. The study was funded by the National Institute on Alcohol Abuse and Alcoholism and the Veterans Affairs Research Service.