Depression and anxiety can take root as early as the very first moments of life.
Certain patterns of brain connectivity seen in newborn babies can predict the baby’s likelihood of showing early symptoms of mental illness ― including sadness, excessive shyness, nervousness and separation anxiety, according to findings published in the February 2017 issue of the Journal of the American Academy of Child and Adolescent Psychiatry. These early symptoms, in turn, are strongly linked with clinical depression and anxiety in older children and adults.
“[Brain connectivity patterns] may indicate that for some children their brains are developing along a trajectory that increases their risk for mental health symptoms as they develop,” Dr. Cynthia Rogers, a child psychiatrist at Washington University in St. Louis and lead study author, told The Huffington Post.
“It’s important to note, however, that the experiences and environment that they are exposed to as they grow may alter these connectivity patterns making it more or less likely for these symptoms to develop.”
The initial aim of the study was to investigate functional connectivity differences between babies born prematurely and those born at full-term. Previous studies had suggested that pre-term babies are at a greater risk of developing psychiatric issues later in life, and the researchers wanted to know whether differences in brain connectivity played a role.
First, the researchers conducted MRI scans on 65 full-term newborns and 57 pre-term babies. The premature newborns were born at least 10 weeks early, but the brain scans were conducted either on or around their original due date. Then, two years later, the researchers assessed the children for early symptoms of depression and anxiety.
When analyzing the brain scans, the researchers focused on how the amygdala ― the brain’s fear center ― interacted with other brain regions.
In contrast to what Rogers expected, the results did not show major differences between the pre-term and full-term babies. They found that both healthy full-term babies and pre-term babies had similar amygdala connectivity patterns to adults, although the strength of these connections was slightly reduced in the premature newborns.
In both premies and full-term babies, stronger connections between the amygdala and the insula (involved in consciousness and emotion) and the medial prefrontal cortex (involved in planning and decision-making) were associated with a higher risk of early signs of anxiety and depression at age two.
This means that there are certain brain patterns already present at birth ― whether the baby is born early or on-time ― that can predict later risk of mental illness.
“Our study is one of the first to detect these functional differences in amygdala connectivity at birth relating to early symptoms,” Rogers explained. “There have been some other studies in older infants and young children that have found functional differences but the advantage of studying infants at birth is these patterns are not influenced by experiences they have had after birth.”
So what does it mean that the premature babies showed slightly weaker connectivity patterns? This may reflect more widespread brain differences in pre-term compared to full-term babies ― but we’re still not sure yet what the lasting impact of those differences might be, according to Rogers.
“These weaker connectivity patterns may suggest who goes on to have symptoms, but even among preterm children there is variability in the connectivity,” Rogers said. “It is also likely that experiences that these children have after birth continue to affect the amygdala connectivity with other brain regions and that may determine who goes on to have impairing symptoms.”
The researchers plan to evaluate the children again when they are 9 and 10 years old to study how their brains have developed over time and to evaluate the lasting impact of the connectivity patterns.
“If we can understand what patterns of connectivity are related to early social and emotional impairments, we can then study what predicts those connectivity patterns,” she said. “We can evaluate whether there are experiences these children have while in the hospital or early in infancy that change these patterns for better or worse that we can aim to modify.”