Are you an anxious person? You might have gotten that from mom and dad.
At least that's what recent research in rhesus monkeys found. A new study identified three parts of the brain that parents may pass down to their kids that could raise the kids' future risk of anxiety disorders.
And past research from the same group of study authors had already found that rhesus monkeys with high anxiety were more likely than calmer monkeys to have anxious offspring.
Now that doesn't necessarily mean that the findings from the past or current study apply to humans, but it still may provide some insight into human anxiety, said lead study author Ned H. Kalin, MD, chair of psychiatry at the University of Wisconsin School of Medicine and Public Health.
"Basically, we think that to a certain extent, anxiety can provide an evolutionary advantage because it helps an individual recognize and avoid danger, but when the circuits are over-active, it becomes a problem and can result in anxiety and depressive disorders," Dr. Kalin said in a press release.
There's a big difference between feeling anxious the night before a test and having an anxiety disorder. For those with chronic anxiety, the feeling doesn't go away after a stressful event is over.
Dr. Kalin and team found that three parts of the brain were overactive in rhesus monkeys that had excessive anxiety. In this case, "overactive" meant that these parts of the brain showed the most activity in a brain scan when the monkeys were feeling anxiety.
The 600 young rhesus monkeys in this study were shown a stranger who would not make eye contact — a situation Dr. Kalin and team said would cause mild anxiety in a child.
In overly anxious monkeys, brain scans showed that the prefrontal cortex (which controls problem solving), the limbic system (which guides emotion and memory) and the brain stem (which controls breathing and heart rate) were overactive.
According to Dr. Kalin and colleagues, this wasn't likely a matter of brain structure — it was more likely a matter of function. Something in the monkeys' genes caused these parts of their brains to overreact to anxiety, these researchers theorized.
That's what Dr. Kalin and team said they believe is passed on from parent to child — the brain function that may contribute to anxiety disorders.
"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. Kalin said.
According to Dr. Kalin and team, this research may bring doctors one step closer to understanding how genes cause anxiety disorders in humans.
This study was published July 6 in the journal Proceedings of the National Academy of Sciences.
No funding sources or conflicts of interest were disclosed.