Heavy drinking and the problematic use of alcohol are widely thought to be relevant factors in assessing an individual’s risk for suicidal behavior. It has been the role of research to investigate exactly how alcohol use and suicidality are related.  

Among the mysteries such research seeks to solve is the question of causality: if one drinks heavily, whether regularly or intermittently, and/or drinks to the point of losing control, might those behaviors directly contribute, in some people, to the conversion of suicidal thoughts to suicidal actions? What is known is that heavy drinkers have about five times greater risk for death by suicide compared with social drinkers. A clinical diagnosis of alcohol use disorder has also been linked with increased risks for suicide attempts and death.

A research team led by 2016 BBRF Young Investigator Alexis C. Edwards Ph.D., sought to understand more about “the complex and potentially shared etiology” (i.e., causation) between alcohol consumption behaviors and suicidality.  They used the results of previously conducted genetic studies called GWAS (genome-wide association studies) to test the hypothesis that genetic risk factors shared by people with alcohol consumption problems and people with a history of suicidal behavior may in turn be correlated with genetic factors associated with the behavioral trait of impulsivity.  

The team wondered: if genetic predisposition to impulsivity does overlap with genetic risk for alcohol problems and suicidal behavior, could that inform efforts in the clinic to identify people early in life whose impulsivity may expose them to elevated risk, later in life, for heavy drinking and suicidality?  (Alcohol and suicidality tend to become problems after early childhood—beginning in adolescence or early adulthood.)

Dr. Edwards and colleagues, including first author of their paper, Mallory Stephenson, employed a recent advance in methodology called Genomic SEM (Structural Equation Modeling) to assess the extent to which genetic liability for impulsivity is correlated with common genetic variations seen in people with alcohol use problems and suicidal behavior.

GWAS studies bring to light locations in the human genome where variations in the DNA sequence occur more often in people with a given diagnosis or behavioral trait than in comparable healthy people or people without the trait.  In the current study, the team’s analysis incorporated summary statistics from GWAS studies of alcohol consumption (involving 160,824 subjects); problematic alcohol use (also 160,824 subjects); alcohol dependence (46,568 subjects); number of alcoholic drinks per week (537,349 subjects); suicide attempt (513,497 subjects); impulsivity (22,861 subjects) and extraversion (63,030 subjects. (Extraversion is the tendency to focus on gratification obtained from sources outside the self.)

In a first phase of analysis the researchers identified a common genetic factor which represented shared genetic signals for risk of excessive alcohol consumption, problems with alcohol use, alcohol dependence, number of drinks per week, and suicide attempt. The next step was to evaluate possible correlations between this common genetic factor and five personality traits involved in impulsivity.   

The five impulsivity traits, which are thought to underlie impulsive action, were: “negative and positive urgency”—which reflect the tendency to engage in rash action when experiencing negative or positive emotions, respectively; “lack of premeditation”—the tendency to act without careful thought or planning; “sensation-seeking”—the tendency to seek out novelty or excitement; and “lack of perseverance”—the inclination to give up before completing a dull or difficult task. Each of these impulsivity traits has varying patterns of association with risky behavior.

What the team hoped to derive from all of these analytical factors was insight into which impulsive personality traits, if any, are associated with shared genetic liability for problematic alcohol use and suicidality.  

They found that the common genetic signal linking problematic alcohol use and suicidality was in turn linked with all five of the impulsive personality traits examined. But the magnitude of these associations varied. The shared genetic signal for alcohol use and suicidality was most strongly correlated with “lack of premeditation.”  

“These findings,” the team noted in their paper appearing in Translational Psychiatry, have potential implications for screening, prevention, and intervention. For instance, we provide very preliminary evidence that early assessment of impulsive personality traits may help identify individuals at risk for the later development of problematic alcohol use and suicidality.”

Just as important, they noted, is that “the cognitive mechanisms underlying lack of premeditation are modifiable and improve with neuropsychological intervention.”

“Our findings provide preliminary evidence that impulsive personality traits may serve as an early indicator of genetic risk for alcohol problems and suicidality,” the researchers wrote.  It will be important, they noted, for future studies to determine if features of impulsivity are part of the causal pathway that leads from genetic risk to actual alcohol problems and suicide attempts in individuals.