Your Anxiety Might Have Started In the Womb, According To This Discovery Researchers Made

In today's world, there are plenty of reasons why you might have anxiety, whether it's due to job stress or the rising cost of living. But a new study suggests that if you struggle with anxiety, it may not just be from the current pressures of society—instead, it could have much deeper roots, all the way back to the womb.

During pregnancy, unhealthy or stressful conditions can rewire the development of a baby's brain in ways that increase their risk of anxiety later in life.

Researchers at Weill Cornell Medicine made this discovery while studying mice. The brains of mice share a similar structure to those of humans, making them an ideal model for experiments on human behavior.

The research team simulated stress in pregnant mice by triggering inflammation. Then, they observed what happened to the offspring.

The scientists found that when mothers experienced stress or infection during pregnancy, their offspring exhibited stronger anxiety responses, even though the baby mice were not genetically predisposed to anxiety.

Brain scans showed hyperactivity in the ventral dentate gyrus (vDG), a region in the brain that detects potential dangers in an environment.

In control mice, activity remained steady in the vDG when they moved from safe to risky areas in a maze. But in mice exposed to prenatal adversity, activity surged when they thought about leaving their safe space and going into a more threatening one.

"The mice seem to anticipate the danger, so the increased activity of the neurons is not a consequence of going into the threatening environment, but precedes it," said Dr. Kristen Pleil, an associate professor of pharmacology at Weill Cornell Medicine and co-leader of the study.

A small group of neurons in the vDG region was rewired to become overly sensitive for these mice. There are nearly 400,000 cells in the vDG of a mouse, but only a few thousand are affected during pregnancy.

julia_popova_ph - stock.adobe.com - illustrative purposes only, not the actual person

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The neurons fired too much in the face of mild danger, meaning the mice perceived the environment as more dangerous than it actually was. As a result, the mice would avoid situations and anticipate threats unnecessarily.

"Our data reveal prenatal adversity left lasting imprints on the neurons of the vDG linking gestational environment to anxiety-like behavior," said Dr. Miklos Toth, a professor in the Department of Pharmacology at Weill Cornell Medicine and co-leader of the study.

"This mechanism may help explain the persistent stress sensitivity and avoidance seen in individuals with innate anxiety."

In humans, the research could explain why some people automatically flinch before danger even shows up. Overall, the new discovery could help lead to better diagnostics and treatments for anxiety in the future, as well as highlighting how important maternal health is for brain function during pregnancy.

The study was published in Cell Reports.