Alcohol and Drug Use Increases Suicidal Behaviors

Summary of working paper 8810
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Suicidal behavior among college students is lower where the price of beer is higher.

Each year more American young people die from suicide than from all other leading natural causes of death combined. In 1997, a sobering 13 percent of deaths among 15 to 24 year olds were the result of suicide. Survey data suggest that between 12 and 25 percent of school age youth consider suicide or make plans to commit suicide. Furthermore, the rate of youth suicide is on an upward path, tripling between 1950 and 1990.

Previous research documents a strong link between drug and alcohol abuse and suicidal behavior. But according to Sara Markowitz, Pinka Chatterji, Robert Kaestner, and Dhaval Dave writing in Substance Use and Suicidal Behaviors Among Young Adults (NBER Working Paper No. 8810), that research does not establish that substance abuse has a causal role in youth's suicide thoughts or actions. Substance abuse can cause social isolation, low self esteem, loss of work or school, estrangement from family and friends - all events that can build a core of stresses that may lead to suicidal tendencies. Substance abuse also can increase impulsiveness and decrease inhibitions, making one more likely to act on suicidal tendencies. But the earlier studies did not adequately explore the effects of other major influences on suicidal behavior, namely depression and other psychiatric problems, nor the idea that suicidal tendencies actually may spur the drinking and drug abuse.

In this paper, the authors conjecture that if substance use causes suicidal behavior, then policies designed to reduce the consumption of alcohol and illegal drugs may succeed in reducing suicidal behaviors. The researchers attempt to uncover the role of alcohol and drug consumption in determining suicidal thoughts and attempts among college age students. Data for their study come from the University of Southern Illinois's Core Institute, which conducts annual surveys of college students, focusing on drinking and drug use. The survey covered approximately 30,000 students in 1991 at both private and public colleges across the United States. The analysis was limited to respondents between the ages of 17 and 24.

Students were asked how often in the past year they "seriously thought about suicide" or "seriously tried to commit suicide" because of alcohol or drug use. Students were also asked about the number of drinks they consumed in a week, if they were binge drinkers (categorized as five or more drinks in a sitting in the past two weeks), and if they used marijuana or any illegal drugs in the past year. Extensive socioeconomic and demographic information was gathered: gender, age, college class year, grade point average, race, marital status, employment status, campus living arrangement, and parental history of alcohol and drug problems. The Core survey did not measure psychiatric disorders, the most important link between substance abuse and suicidal tendencies. However, the study includes information about students' smoking, which has been shown to be a correlate of psychiatric disorders and other substance use.

The results show that students who drink or use drugs are much more likely to have suicidal tendencies than those who do not use substances. For example, 8.15 percent of binge drinkers have thought about committing suicide and 2.34 percent report attempting suicide. Similar comparisons hold for students who drink at all, who use marijuana, and who use other illegal drugs. Only 2.34 percent of non-drinkers have thought about committing suicide with only .78 percent attempting suicide. Markowitz and her co-authors contend, "It is important to note that these results establish a correlation between substance use and suicidal behaviors, but do not address the issue of causality."

The authors also estimate a model that relies on factors that are believed to be correlated with substance use but not suicidal behaviors (such as the price of beer and living arrangements) to test the nature of this association. The results are consistent with a causal relationship from alcohol and illicit drug consumption to suicidal behaviors. Many of the student characteristics are also important determinants of suicidal behaviors. Being older and having a higher grade point average both reduce the probability of suicidal thoughts and attempts, while being female increases these probabilities. Part-time students are more likely to engage in suicidal thoughts and attempts. Being married lowers the probability of suicidal thoughts, while being divorced increases both thoughts and attempts.

Using a similar model that centers on the beer price, the authors find that suicidal behavior among college students is lower where the price of beer is higher. Furthermore, students living on campus are found to be more likely to engage in suicidal behaviors because of their higher drug and alcohol use than those living off campus.

In conclusion, the authors suggest that alcohol and drug use increases the likelihood of suicidal thoughts and attempts. Therefore, policies designed to prevent substance abuse may also prevent suicidal behaviors among college students. According to the authors, "This research is a first step towards expanding policymakers' ability to prevent suicidal behaviors, and their tragic consequences, among college students."

-- Marie Bussing-Burks