It's well known that early life experiences can affect a child's cognitive, emotional, and behavioral development. A recent study funded by NIMH takes this link one step further showing that negative childhood experiences, such as abuse or neglect, can affect a person's physical health as well. Published in the February 24, 2009, issue of the Proceedings of the National Academy of Sciences, the study suggests a history of child abuse or neglect can lower a person's overall immunity and ability to manage stress, and that this effect may be long-lasting.
Seth D. Pollak, Ph.D., University of Wisconsin, and colleagues compared immune function among 155 teens, ages 9â€“14, categorized into three groups:
- "Early adversity," teens who spent the early part of their lives in orphanages or other institutions but were adopted from 3.5-13 years prior to the study
- "Current adversity," teens who had been physically abused at home and continued living with their biological families
- Matched controls who were neither adopted nor experienced abuse.
The researchers collected saliva samples from the teens over four days, checking for antibodies to the herpes simplex virus (HSV). Many people have HSV, known for causing cold sores, but properly functioning immune systems keep the virus under control. Past studies on HSV have shown that stressful life events increase the level of HSV antibodies, which can be measured in a person's blood or saliva.
Results of the Studies
Both groups of teens who had faced adversity early in life had higher than normal levels of HSV antibodies. This result suggests that childhood maltreatment reduces immune function, an effect that can linger long after the adverse experience has ended.
According to the researchers, their findings emphasize the importance of having supportive and functional family relationships during childhood. Negative experiences early in life can have long-lasting effects on physical health, in addition to the known mental health consequences.
Future studies should explore other early life factors that may affect adult physical health. Such research can help inform efforts to screen and treat populations at risk for poor health outcomes, or possibly even prevent certain illnesses.
Shirtcliff EA, Coe CL, Pollak SD. Early childhood stress is associated with elevated antibody levels to herpes simplex virus type 1. Proc Natl Acad Sci U S A. 2009 Feb 24;106(8):2963-7. PMID: 19188604