Childhood Stress and Lifelong Health
New research indicates adverse effects on physical health, for decades.
Posted November 16, 2010
Parents are always worried when their child encounters stress or trauma. We all know it is bad for children to be victimized by bullies, to witness physical violence, to be mistreated by an adult, or to have basic needs such as shelter, food, or affection neglected. Most, though not all, children who suffer adverse experiences develop behavioral or emotional problems as a result.
What is less well-known is that stressful experiences can also lead to hidden physical alterations in a child's body. In adults, these alterations are known to be associated with elevated risk of heart disease, immune diseases, stroke, and even dementia. When a child is mistreated, we tend to focus on the child's symptoms of anxiety, depression, or aggressive reactions. But new research indicates there can also be adverse effects on a child's physical health, for decades into his or her future. For a child, mistreatment by others can physically be heartbreaking immediately and in the long term.
Our research team uncovered these hidden changes in physical health that emerge from childhood stress by following two cohorts of children from birth onward. In one study, we track 1000 boys and girls who were born in the 1970's in New Zealand. In the second, we track 2200 children born in the 1990's in Britain. For all of these years, we have recorded the serious stressful experiences in each child's life, and assessed the children's mental health throughout. Now, we have begun to evaluate their physical health too, including so called "biomarkers," medical tests that reveal hidden changes likely to lead to serious health problems later in life.
We have published reports that New Zealand children mistreated in the first decade of their lives show elevated levels of biomarkers (C-reactive protein, fibrinogen, white blood cell count) by the age of thirty. These biomarkers signal inflammation. When we studied the children born more recently in Britain, some of those mistreated in the first decade already indicate mildly abnormal inflammation by the age of twelve. Other researchers have previously demonstrated the inflammation biomarkers as predictors for heart attacks and dementia in adults. Not all of the mistreated children in our studies show abnormal biomarkers and it is still not entirely clear why some do and some do not. Those who do show biological changes also demonstrate serious emotional symptoms of depression and anxiety.
This information is exciting to scientists and parents alike because it opens the door to early intervention and even prevention. Life expectancy is growing longer and longer. Demographic trends tell us that the current generation of children may live well beyond 100 years of age. Of course, we all want these extra years of life to be healthy, productive and enjoyable, not years of disease, disability, and dependence on others. Past medical research has shown that treating patients after they have contracted illnesses such as cardiovascular disease, diabetes, or dementia generally does not fully restore their quality of life. The hope of increasing our children's lifelong productivity, health and well being calls for research to identify prevention methods that can be applied well before a disease takes hold.
Stressors that precipitate emotional problems for young children can also damage their lifelong health. The burden of adult diseases could be reduced if we can improve the psychological well-being of all children. Great strides have been made toward designing effective treatments for children with emotional and behavioral problems, but only a fraction of these children receive them. But if c good psychological health in childhood is understood to be essential for good physical health in people over 50, clinical child psychology may well become a key weapon in the fight to improve everyone's quality of life in old age.
Professors Terrie Moffitt and Avshalom Caspi are being awarded $1 million from the Jacobs Foundation in Switzerland for their contributions to the field of child psychology on December 3, 2010.