However, different types of adversity were associated with cortical thinning in different parts of the brain. They found that adversity was associated with reduced cortical thickness - a sign of aging because the cortex thins as people age. In a second analysis, McLaughlin and her colleagues systematically reviewed 25 studies with more than 3,253 participants that examined how early-life adversity affects brain development. However, children who experienced poverty or neglect did not show either of those signs of early aging. They found that children who suffered threat-related trauma such as violence or abuse were more likely to enter puberty early and also showed signs of accelerated aging on a cellular level-including shortened telomeres, the protective caps at the ends of our strands of DNA that wear down as we age. The researchers performed a meta-analysis of almost 80 studies, with more than 116,000 total participants. To disentangle the results, McLaughlin and her colleagues decided to look separately at two categories of adversity: threat-related adversity, such as abuse and violence, and deprivation-related adversity, such as physical or emotional neglect or poverty. However, those studies looked at many different types of adversity - abuse, neglect, poverty and more - and at several different measures of biological aging. Previous research found mixed evidence on whether childhood adversity is always linked to accelerated aging.
"Our study suggests that experiencing violence can make the body age more quickly at a biological level, which may help to explain that connection." "Exposure to adversity in childhood is a powerful predictor of health outcomes later in life - not only mental health outcomes like depression and anxiety, but also physical health outcomes like cardiovascular disease, diabetes and cancer," said Katie McLaughlin, PhD, an associate professor of psychology at Harvard University and senior author of the study published in the journal Psychological Bulletin.