Experiencing emotional hardships before age 6, such as family instability or abuse, is tied to changes in brain structure. These changes appear to create a higher risk of anxiety or depression, according to a study conducted in England.
The study followed almost 500 pairs of mothers and sons from before the birth of the sons until the boys were 18 to 21 years old. At several points from infancy to age 6, the mothers answered questions about 37 types of "adversity" in the home, including loss of a family member, family instability, and abuse toward the child or mother.
When the boys were 7, 10, and 13 years old, the mothers reported on symptoms of anxiety or depression, which the study called internalizing symptoms. Risk factors were seen to be adversity within the first 6 years of the child's life (including prenatal exposure) and the child's internalizing symptoms between age 7 and age 13. Early adversity was also associated with higher levels of internalizing symptoms.
Then, when the boys were between age 18 and 21, they underwent magnetic resonance imaging (MRI) of their brains. According to the scans, having experienced more types of adversity before age 6 was associated with lower gray matter volume in an area of the brain that is involved in emotion, decision-making, and empathy. There was a higher volume of gray matter in a part of the brain involved with episodic memory. Early adversity was also tied to lower volume in a part of the brain called the right superior frontal gyrus of the brain, as were later symptoms of anxiety and depression, the researchers reported.
"These findings may suggest that some of the structural variation often attributed to depression might be associated with early adversity in addition to the effect of depression," the report stated.
"Most children will experience a degree of adversity, but this is not necessarily harmful," senior author Edward D. Barker of the Institute of Psychiatry, Psychology, and Neuroscience at King's College London said to Reuters Health by email. "Our research suggests that children who experience many forms of adversity are at risk."
The study was published in the journal JAMA Pediatrics.