According to a recent American Psychological Association poll, nearly a quarter of Americans confessed to currently feeling under "extreme stress." Respondents especially blamed money, work, and the economy—a feeling 50-year-old Sue Wasserman knows all too well. In February, the public relations manager left Atlanta after her job was eliminated by a corporate restructuring and took a new post in Asheville, N.C. When that proved a bad fit, she struck out on her own as a freelance writer and publicist. Though Wasserman is thrilled some days to be living near the Blue Ridge Mountains, the uncertainty of her income overwhelms her. "There's a sense of foreboding—of 'What did I just do?' " she says.
Short periods of tension can actually be beneficial to people, sharpening thinking and heightening physical response in situations where performance counts, such as business meetings or athletic competitions. But experts are clear that when individuals are routinely under assault—over money, health woes, a daily freeway commute, whatever—a biological system that was designed to occasionally fight or flee a predator gets markedly out of balance. "The body's delicate feedback system starts to malfunction," says David Spiegel, director of the Center on Stress and Health at Stanford University.
Stress has been found to play a role in so many diseases of modern life—from asthma, depression, and migraine flares to heart attacks, cancer, and diabetes—that it likely accounts for more than half of the country's healthcare-related expenses, says George Chrousos, a distinguished visiting scientist at the National Institutes of Health. In March, Chrousos spearheaded a conference on "The Profound Impact of Stress" in Washington, D.C., to educate policymakers and the public.
For decades, researchers have worked to unlock the scientific puzzle of how stress pervades and influences so many organ systems. In recent years, with an improved knowledge of biology and advanced laboratory techniques, they have produced a picture that identifies many more complex, and longer-lasting, effects than were previously understood.
One of the more disconcerting findings is that children (and perhaps even unborn babies) exposed to extreme emotional stressors may face a lifetime of consequences. "Children are extremely vulnerable to stress, because of their rapidly developing brain and their lack of prior experience with it," Chrousos says. In early March, Duke University scientists reported that twins ages 5 to 10 who had been targets of frequent bullying or physical assault or who watched their mothers become victims of domestic violence showed signs of premature aging in their cells, a risk factor for many diseases in adulthood.
Even more disturbing research reported in summer 2011 by German scientists and researchers at the University of California found that fetuses can be affected by their mother's emotional stress. Young adults whose mothers experienced a major event while pregnant with them, such as the loss of their home or the death of a relative, also had significant premature cell aging. Still, moms-to-be should not be too concerned, cautions Roberto Romero, chief of the Perinatology Research Branch of the National Institute of Child Health and Human Development, who was not involved with the research. For one thing, more studies are needed to confirm the findings. Moreover, these moms experienced highly traumatic events. "There's no evidence of a deleterious effect when pregnant women face the regular modern-life stressors of having 200 E-mails in their inbox," he says.
A chemical cascade. How does stress cause so much physical harm? In adults, at least, experts know that one route is its direct effect on the cardiovascular system. Lab studies confirm that blood pressure and heart rates rise in response to a stressor. Incidents of heart attacks also increase. After the big central California earthquake of 1983, heart attacks killed more people than the quake itself, says Noel Bairey Merz, director of the Cedars-Sinai Barbra Streisand Women's Heart Center in Los Angeles, who notes that victims likely already had some level of heart disease. Another mechanism: the poor habits people readily adopt during periods of prolonged tension. "People who are under stress are more likely to gain weight and to smoke, and are less likely to sleep well or exercise," which can lead to cardiovascular and other diseases, Bairey Merz says.