Anxious children may have a "fear center" in the brain, according to a recent study.

Researchers from the Stanford University School of Medicine found that alterations in the development of the amygdala, which is a key "fear center" in the brain, may have an important influence on the development of anxiety problems. Children with high levels of anxiety had enlarged amygdala volume and increased connectivity with other brain regions responsible for attention, emotion perception, and regulation, compared to children with low levels of anxiety.

"Our study represents an important step in characterizing altered brain systems and developing predictive biomarkers in the identification for young children at risk for anxiety disorders," Dr. Shaozeng Qin, first author of the study, said in a statement.

For the study, researchers recruited 76 children between the ages of 7 and 9, a period when anxiety-related traits and symptoms can first be reliably identified. The children's parents completed assessments designed to measure the anxiety levels of the children, and the children then underwent non-invasive magnetic resonance imaging (MRI) scans of brain structure and function.

They found that the most affected region was the basolateral portion of the amygdala, a subregion of the amygdala implicated in fear learning and the processing of emotion-related information.

"It is a bit surprising that alterations to the structure and connectivity of the amygdala were so significant in children with higher levels of anxiety, given both the young age of the children and the fact that their anxiety levels were too low to be observed clinically," Qin said.

Qin added that their findings will provide important new insights into the neurodevelopmental origins of anxiety in humans.

The findings were recently published in Biological Psychiatry.