Report identifies early childhood conditions that lead to adult health disparities

The origins of many adult diseases can be traced to early negative experiences associated with social class and other markers of disadvantage.

Confronting the causes of adversity before and shortly after birth may be a promising way to improve adult health and reduce premature deaths, researchers argue in a paper published today in JAMA: The Journal of the American Medical Association. These adversities establish biological "memories" that weaken physiological systems and make individuals vulnerable to problems that can lie dormant for years.

"Improving the developmental trajectory of a child by helping the parents and improving the home environment is probably the single most important thing we can do for the health of that child," says co-author Bruce McEwen, Alfred E. Mirsky Professor and head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at The Rockefeller University. "Adverse childhood experience is one of the largest contributors to such chronic health problems as diabetes and obesity, psychiatric disorders, drug abuse - almost every major public health challenge we face."

In the report, McEwen and his co-authors distinguish between levels of stress experienced by young children. "Positive" and "tolerable" stress, with the support of adults, help the body and brain learn to cope with brief situations of adversity, while "toxic" stress, which can disrupt brain architecture and other organ systems, increases the risk for stress-related disease and cognitive impairment well into adulthood. Major risk factors for toxic stress include extreme poverty, recurrent physical and/or emotional abuse, chronic neglect, severe maternal depression, parental substance abuse, and family violence.

An intervention to relieve toxic stress that children experience early in life could not only affect their own individual well-being and longevity but also improve overall societal health, the report concludes. In particular, the researchers highlight three findings and propose promising applications in health policy and clinical practice:

• Adult disease prevention begins with reducing toxic stress in early childhood, as a reduction in the number and severity of early adverse experiences will lead to a decrease in the prevalence of a wide range of health problems.
• High-quality early care and education programs can benefit lifelong health, not just learning, by providing safe, stable, responsive environments and evidence-based treatments for family mental health problems.
• Child welfare services represent an opportunity for lifelong health promotion by augmenting their exclusive focus on child safety and custody with comprehensive developmental assessments and appropriate interventions by skilled professionals.

"Health care reform is clearly essential for assuring universal access to needed medical care," says co-author Jack Shonkoff, founding director of the Center on the Developing Child at Harvard University. "Yet we also know that health disparities linked to social class, race, and ethnicity are not primarily about health care access or quality, since these inequalities persist in countries that provide health care for all their citizens. These disparities are rooted in where and how we live, work, and play. Science is now telling us that they're also about how we as a society treat our youngest members."

McEwen and Shonkoff wrote the report with W. Thomas Boyce, the chair in child development and professor in the College for Interdisciplinary Studies and Faculty of Medicine at the University of British Columbia. All three authors are members of the National Scientific Council on the Developing Child, a multi-disciplinary, multi-university collaboration housed at the Center on the Developing Child at Harvard University.

JAMA: Vol. 301(21), June 3, 2009
Building a New Framework for Health Promotion and Disease Prevention
Jack P. Shonkoff, MD; W. Thomas Boyce, MD; Bruce S. McEwen, PhD