An analysis of several brain scans of monkeys showed that parents suffering from anxiety and depression are likely to pass those feelings to their children. The study provides evidence that anxiety and depression are hereditary.
Researchers at the University of Wisconsin-Madison observed 600 rhesus monkeys that came from an extended family. They exposed the young monkeys to a situation and used brain imaging to identify which region of the brain is affected by depression and anxiety.
The subjects were exposed to a stranger with no eye contact. During the process, the researchers observed increased activity in the prefrontal-limbic-midbrain circuit of the brain. These areas control the in-born risk for anxiety that can be observed in early childhood.
The analysis showed that parents are likely to pass their anxiety and depression to their children by 35 percent. The researchers used a "genetic correlation" approach to determine how these negative feelings are imprinted on the genes of the parents.
"Over-activity of these three brain regions are inherited brain alterations that are directly linked to the later life risk to develop anxiety and depression," Dr. Ned Kalin, senior author and chair of psychiatry at the UW School of Medicine and Public Health, said in a press release. "This is a big step in understanding the neural underpinnings of inherited anxiety and begins to give us more selective targets for treatment."
The findings remain the same after considering the brain size of the monkeys. However, the researchers admitted that further study is needed to prove the theory of genetic imprinting of anxiety and depression.
"Now that we know where to look, we can develop a better understanding of the molecular alterations that give rise to anxiety-related brain function,'' Kalin said. "Our genes shape our brains to help make us who we are."
The study was published in the July 1 issue of the Proceedings of the National Academy of Sciences.