Anxiety Could Be an Inherited Condition, and Scientists Think They Know Why

If you have an anxiety disorder, you might be able to blame your parents for it. A new study in The Journal of Neuroscience reveals that some monkeys may pass a tendency toward anxiety down from generation to generation, and it might work the same way in humans, Science Alert reports.

It's known that anxiety can run in families, but how the heritability of anxiety works, and which areas of the brain are involved, is more mysterious. Researchers at the University of Wisconsin-Madison used functional magnetic resonance imaging (fMRI) to monitor the brain activity of 378 young rhesus macaques who were placed in an anxiety-inducing situation. For the study, a person stood in their cage and avoided eye contact with the monkeys for 30 minutes, which likely made the monkeys wonder whether their visitor was a potential threat. It’s the same approach often used in psychology labs to study anxiety in children, the study’s co-author tells Discover.

After analyzing the results of the stress test, scientists discovered increased activity in two regions of the amygdala—the part of the brain that processes fear and other emotions—in monkeys that had outwardly expressed the most anxiety. Using information about the monkeys’ lineage dating back eight generations, scientists determined that the ancestors of the high-anxiety monkeys had elicited a similar brain response. In other words, their anxiety may have been inherited. Genetics aren't fully to blame for anxiety, however, because environmental factors are often at play.

Because of the similarities between monkeys and humans, the results could lend insight into treatments for children with extreme anxious temperament (AT), which often develops into an anxiety disorder later in life. "Looking first at the monkeys has provided us with clues about which systems to focus on in our studies of at-risk young children," senior author Ned Kalin said in a statement.

Studies like this may help lay the groundwork for addressing the underlying cause of anxiety, rather than just treating the symptoms.