Researchers believe genetics can influence impulsivity and other forms of risky behavior, especially among males — a link supported by a new study from the University of Nebraska-Lincoln.
Dr. Scott Stoltenberg, an assistant professor in the Psychology Department, found links between impulsivity and a rarely researched gene called NRXN3. The gene plays an important role in brain development and in how neurons function.
The newly discovered connection, which was more prevalent among men than women in the study, may help explain certain inclinations toward alcohol or drug dependence, Stoltenberg said.
“Impulsivity is an important underlying mechanism in addiction,” he said. “Our finding that NRXN3 is part of the causal pathway toward addiction is an important step in identifying the underlying genetic architecture of this key personality trait.”
During the investigation, researchers measured impulsivity levels in nearly 450 participants — 65 percent women, 35 percent men. They then compared the findings with DNA samples from each participant.
Researchers discovered impulsivity was significantly higher in those who regularly used tobacco or who had alcohol or drug problems. They also discovered that gender played a role.
In men, two connections clearly emerged; first, between a particular form of the NRXN3 gene and attentional impulsivity, and second, between another NRXN3 variant and alcohol problems.
The connections for women, meanwhile, were much weaker.
Stoltenberg said the gender-specific results are a rich area for further study.
“We can’t really say what causes these patterns of association to be different in men and women. But our findings will be critical as we continue to improve our understanding of the pathways from specific genes to health-risk behaviors,” he said.
Impulsivity was studied because the trait can predispose people to any number of behavioral problems — addictions, behavior control, failing to plan ahead or think through consequences of actions. Researchers selected the gene NXRN3 as a biomarker because of prior studies that had established the linkage.
The results add important new evidence to the genetic role in impulsivity –and, in turn, its role in substance abuse.
However, researchers were careful to point out that the this is not a perfect cause-and-effect relationship. That is, impulsivity alone may not cause substance abuse. However, impulsivity may interact with sensitivity to alcohol, for one example, or anxiety, for another, to create complex pathways to substance use problems in both men and women.
“If you’re working to explain how genes are associated with something like (substance) dependence, you have to connect a lot of dots,” Stoltenberg said.
“There’s a big gap between genes and a substance use disorder. Impulsivity is one factor to such problems — not the only factor.”
Source: University of Nebraska-Lincoln