Children who experience violence or trauma seem to age faster, undergo puberty earlier and show greater signs of aging in their cells, researchers have found.
They say that the results contribute to a growing amount of work that suggests that early adversity can be “biologically embedded” with the potential for negative health effects later in life.
McLaughlin and her colleagues wrote in the Psychological Bulletin and describe how they analyzed 54 studies that looked at the effects of two forms of adversity at the beginning of puberty and aging markers in cells.
In both cases, the results reveal children who had experienced violence or trauma, but not deprivation, showed accelerated aging compared to those who had not.
The figures varied between different studies, but repeated exposure to violence seems to be linked to girls who experience menarche up to several months earlier than their peers. Although a small effect, the team says it may be important, notes that earlier puberty has been linked to mental and physical health problems later.
Regarding cellular aging – measured by the shortening of telomeres, the caps at the end of chromosomes and the accumulation of methyl groups on DNA – the team says that children who experienced violence or trauma seemed to be months or even years older than they really were.
“We know [these measures] are very powerful predictors of health outcomes and even mortality later in life, says McLaughlin. Studies in adults suggest that faster biological aging at the cellular level is associated with an increased risk of conditions from cancer to cardiovascular disease.
The team also examined another 25 studies on the effects of childhood adversity on the thinning of the cortex, the outer layer of the brain, which occurs with age and is linked to an increase in treatment effectiveness.
“What we see is growing up in a dangerous environment accelerates the process for regions of the brain that process social and emotional information and help us identify and respond to threats,” McLaughlin said. It may be beneficial in the short term, but other work suggests that such changes may be linked to an increased risk of mental health problems, she said.
Accelerated thinning was also seen in children who experienced deficiencies but in different parts of the brain, including those associated with memory and decision making.
For all markers of aging, the effects of the childhood resistance scale with the extent or severity of the experience appeared. The team notes that only a small number of studies were examined for each aging measure, and that the role of genetic heredity in the findings requires further review.
However, McLaughlin said it made sense that different forms of adversity had different effects. “The types of adaptations that are likely to help children adapt to a dangerous environment are very different from those that may be needed in an environment that is deprived,” she said.
Andrea Danese, Professor of Child and Adolescent Psychiatry at Kings College London, welcomed the research. “The results suggest that a more detailed assessment of children’s experiences may provide information about their underlying risk of biological aging,” he said.
“In turn, this may guide further research to understand why age-related conditions, such as cardiovascular disease or certain forms of diabetes, are more common in individuals who have experienced childhood resistance.” …
However, he also said that the differences were small, which means that they could not be used to target individual children. It was not clear why threatening experiences such as violence are linked to faster aging.
“Threat experiences are associated with several characteristics of the child, the family and society, which can account for the observed differences and should be better understood,” he said. “This will enable us to strengthen causal inference and inform the development of effective interventions to alleviate the health burden associated with negative childhood experiences.”