NIH-led study identifies genetic variant that can lead to severe impulsivity
A research team has found a genetic variant that may contribute to violently impulsive behavior. Impulsive behavior, or actions without foresight, is a factor in many pathological behaviors—including suicide, aggression, and addiction—but it is also a trait that can be of value if a quick decision must be made or in situations where risk-taking is favored.
Balintfy: Experts define impulsivity as action without foresight.
Goldman: Impulsivity is a normal dimension of behavior.
Balintfy: That’s Dr. David Goldman, chief of the Laboratory of Neurogenetics, at the National Institute on Alcohol Abuse and Alcoholism.
Goldman: But it’s also a dimension of behavior that can be involved in some significant psychiatric diseases.
Balintfy: He adds impulsivity plays a role in suicide, for example, and other diseases like alcoholism and other addictions.
Goldman: So in trying to understand these diseases, we’ve studied their components, such as impulsivity. And for our study, we DNA-sequenced people who were extremely impulsive.
Balintfy: Those extremely impulsive people were violent criminal offenders in Finland whose crimes were notably spontaneous and purposeless.
Goldman: And by sequencing these genes in these severely impulsive individuals, we were able to find a common severe genetic variant.
Balintfy: Dr. Goldman explains that modern Finns are descended from a relatively small number of original settlers, which means the genetic complexity of diseases in that country is reduced. Studying the DNA of violent criminal offenders within Finland increased the chances of finding the gene that influences impulsive behavior. It turns out:
Goldman: Everybody has this gene, and also everybody has severe genetic variants of this nature. But everybody doesn’t have this particular severe genetic variant. In fact, it's found in over hundred-thousand Finns, but so far we haven’t seen it in any other population world wide.
Balintfy: And, Dr. Goldman notes, the genetic variant alone was insufficient to cause people to act impulsively.
Goldman: While there are people who are severely impulsive, who have this genetic variant… there are many people who carry it who are not.
Balintfy: He says the gene is sometimes necessary, but never sufficient. And he adds the discovery in this study does not mean impulsivity is explained.
Goldman: We know that there are genetic factors in impulsivity, just like there are for all of the major personality traits. These personality traits, including impulsivity, are from 40-60 percent inherited and that means there are genes at the base that influencing those. These are genes that are inherited from our parents and that are shared to some extent between us and our brothers and sisters. And so, what it does mean is that we’ve made some progress in beginning to identify the specific genes that are responsible for that general inheritance.
Balintfy: In the study, carriers of the gene variant who had committed impulsive crimes were male, and all had become violent only while drunk from alcohol. For more on this study, and impulsivity, visit www.niaaa.nih.gov. This is Joe Balintfy, National Institutes of Health, Bethesda, Maryland.
About This Audio Report
Reporter: Joe Balintfy
Sound Bite: Dr. David Goldman
Topic: impulsivity, impulsive, impulse, gene, genetic variant, behavior