Early indicators of anxiety and depression may be evident in a newborn baby’s brain, according to new research published in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP).
For the study, researchers analyzed brain scans of newborns and found that the strength and pattern of connections between the amygdala and certain brain regions was tied to the child’s risk of developing greater internalizing symptoms such as sadness, excessive shyness, nervousness, or separation anxiety by age two. These early symptoms are linked to clinical depression and anxiety disorders in older children and adults.
“The fact that we could see these connectivity patterns in the brain at birth helps answer a critical question about whether they could be responsible for early symptoms linked to depression and anxiety or whether these symptoms themselves lead to changes in the brain,” said Cynthia Rogers, M.D., an assistant professor of child psychiatry. “We have found that already at birth, brain connections may be responsible for the development of problems later in life.”
Initially, the researchers wanted to investigate any differences in functional brain connectivity — the coordination of activity across different parts of the brain — between premature and full term babies. They scanned the brains of 65 full-term newborns and 57 premature infants born at least ten weeks early. The premature babies were scanned on or near their due dates.
The researchers looked for differences in connectivity patterns across several regions of the brain hoping to figure out why premature infants face a greater risk of developing mental disorders — including depression and anxiety — later in life. In particular, they focused on how the amygdala, a brain structure involved in the processing of emotions, connects with other brain regions.
The findings reveal that connectivity patterns between the amygdala and other regions of the brain in healthy, full term babies were similar to those found in adults. Although there were similar patterns of connectivity in premature infants, the strength of their connections between the amygdala and other brain regions was decreased.
Furthermore, connection patterns between the amygdala and other structures — like the insula, which is involved in consciousness and emotion, and the medial prefrontal cortex, which plays roles in planning and decision making — were associated with early symptoms related to depression and anxiety.
When the babies turned two years old, a subset of 17 full-term babies and 27 premature babies received follow-up assessments to look for early symptoms of anxiety and depression.
“Children born prematurely were no more likely than full-term children to exhibit early signs of anxiety and depression,” Dr. Rogers said. “Part of that may have been due to the fact that a number of the full-term children already were at risk for symptoms due to socio-demographic factors, such as living in poverty or having a mother with clinical depression or an anxiety disorder. Further, the severity of these early anxiety symptoms was correlated with connectivity patterns seen in the infants in both groups.”
The researchers hope to observe the children again when they are nine to 10 years old to learn whether brain connections continue to influence the risk for depression and anxiety disorders.
“We have a grant under review to bring the preterm children back when they are older, along with the full-term children, and we want to study how their brains have developed over time,” said Rogers. “We want to determine whether they still have many of the same differences in connectivity, whether there have been any changes in the structural and functional connections in their brains, and how all of that relates to whether they have symptoms of psychiatric disorders.”