Observers have noted parallels between aggression and addiction. People with either problem pursue a harmful behavior, even despite negative consequences. A new study by scientists at the National Institute on Drug Abuse’s (NIDA) Intramural Research Program (IRP) showed that when mice are exposed to experimental protocols adapted from those that are used to model human addictive behaviors, some animals develop an addiction-like propensity to aggression.
Image by NIDANIDA IRP researchers observed that about 70 percent of the male mice pressed a lever in their cages for the opportunity to show aggression toward a mouse of a smaller, subordinate strain. About 19 percent were “compulsive aggression-seeking” animals who worked harder (lever pressed more times) for a chance to aggress, and were more likely to continue lever pressing even when doing so meant forgoing food.
The researchers conclude that under certain conditions, a portion of the mouse population is susceptible to developing compulsive aggression. They hypothesize that this susceptibility is a product of evolution, that it involves some of the same motivational circuits in the brain that are disrupted in addiction—and that it may also occur in people. Their findings also indicate that the same animal models researchers have developed to investigate addiction can also be used to study compulsive aggression.
Study:
- Golden SA, Heins C, Venniro M, Caprioli D, Zhang M, Epstein D, Shaham Y. Compulsive addiction-like aggressive behavior in mice. Biological Psychiatry. http://dx.doi.org/10.1016/j.biopsych.2017.03.004