The University of Wisconsin-Madison issued the following news release:
Early childhood stress has lingering effects on health
Stressful experiences in early childhood can have long-lasting impacts
on kids’ health that persist well beyond the resolution of the situation.
The conclusion comes from a study revealing impaired immune function in
adolescents who, as youngsters, experienced either physical abuse or
time in an orphanage, when compared to peers who never experienced such
difficult circumstances. The report from the University of Wisconsin-
Madison appears online the week of Jan. 26 in the Proceedings of the
National Academy of Sciences.
“Even though these children’s environments have changed, physiologically
they’re still responding to stress. That can affect their learning and
their behavior, and having a compromised immune system is going to
affect these children’s health,” says senior author Seth Pollak, a
professor of psychology and pediatrics at UW-Madison.
As director of the Child Emotion Laboratory in the UW-Madison Waisman
Center, Pollak focuses on how experiences early in life affect
children’s subsequent development. In the current work, he and fellow
Wisconsin psychology professor Chris Coe, an expert on the links between
stress and immunity, turned to the immune system as a way to isolate the
consequences of early events.
“The immune system is not preset at birth,” says Coe. “The cells are
there, but how they will develop and how well they’ll be regulated is
very much influenced by your early environment and the type of rearing
Led by Elizabeth Shirtcliff of the University of New Orleans when she
was a postdoctoral fellow at UW-Madison, the authors evaluated immune-
system strength among adolescents who had experienced either typical or
unusually stressful childhoods. The researchers looked for high levels
of antibodies against the common and usually latent herpes simplex virus
type 1 (HSV-1).
While roughly two-thirds of Americans carry this virus, which causes
cold sores and fever blisters, people with healthy immune systems are
able to keep the virus in check and rarely if ever have symptoms —
typically, only when stress or illness taxes the immune system. However,
people with weakened immune systems may have trouble suppressing HSV-1
and produce antibodies against the activated virus.
“We can use the control of latent viruses as one way of assessing the
competence of the immune system,” Coe explains. “During times of stress
or if the immune system is not appropriately regulated, the herpes virus
is more likely to reactivate.”
A group of adolescents with documented incidents of past physical abuse
and stressful home environments had higher levels of HSV-1 antibodies,
showing that their immune systems were compromised.
“That is very unfortunate, but it was not surprising,” Pollak says,
since stress is widely known to have negative impacts on immune
function. “It suggests that children’s emotional environments are having
widespread repercussions on their health.”
What was more surprising, however, was that another group of adolescents
in the study, who spent time in orphanages in Romania, Russia or China
before being adopted by U.S. families, showed a similar impairment of
“These children began their lives in a stressful environment, but
they’re now adolescents, and for a decade, they’ve been living in
stable, affluent, loving environments. And yet, their immune systems are
compromised as well. In fact, they look just like the physically abused
kids,” says Pollak.
While antibodies are typically measured in blood, the researchers used
saliva instead to eliminate any acute stress related to collecting the
samples. There was no difference among the groups in likelihood of
carrying HSV-1, so the results reflect a difference only in the ability
to fight its activation.
“The bottom line is that these early stressors can really have long-term
implications,” Pollak says.
He is particularly concerned about the implications of his findings
given the current economic downturn. International adoptions are
expensive and will likely become harder for many U.S. families, leaving
greater numbers of children in institutional settings for longer periods
The work was supported by grants from the National Institute of Mental Health.