Maybe the Meek Won't Inherit the Earth After All - Shyness Can Be Deadly

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Public release date: 15-Dec-2003

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University of California - Los Angeles

Shyness can be deadly

How you react to stress influences how easily you resist or succumb

to disease, including viruses like HIV, discovered UCLA AIDS

Institute scientists. Reported in the Dec.15 edition of Biological

Psychiatry, the new findings identify the immune mechanism that makes

shy people more susceptible to infection than outgoing people.

" Since ancient Greece, physicians have noticed that persons with

a 'melancholic temperament' are more vulnerable to viral infections, "

said Steve Cole, principal investigator and assistant professor of

hematology-oncology at the Geffen School of Medicine and a

member of the UCLA AIDS Institute.

" During the AIDS epidemic, researchers found that introverted people

got sick and died sooner than extroverted people, " said Bruce

Naliboff, co-author and a clinical professor at the UCLA

Neuropsychiatric Institute and Veterans Affairs Greater Los Angeles

Healthcare System. " Our study pinpoints the biological mechanism that

connects personality and disease. "

The UCLA team studied the effect of stress on viral replication in a

group of 54 HIV?infected men. All of the men were still in the early

stages of the disease and in good health. Each possessed high T-cell

counts with detectable levels of virus in the blood.

The researchers put each man through a series of stress tests in the

lab to measure the response of their autonomic nervous system. First,

the scientists monitored the subject's response to a tiny stimulus,

such as an unexpected beeping sound. They measured his heart rate,

skin moisture and dilation of the blood vessels, which contract

during stress to reroute blood to the legs for fight or flight.

" Shy persons didn't adapt to the beeps as fast as other people, " Cole

said. " Their heightened nervous system response indicated that the

sound was more irritating to them. "

Next, each man was required to perform physical exercises, such as

deep breathing or standing from a seated position, both of which

require the nervous system to adapt quickly. Finally, scientists

asked each man to perform rapid mental arithmetic, replying curtly if

the subject provided the wrong answer and requiring him to start

over.

To gauge the subject's overall " stress personality, " the UCLA team

ranked each man by totaling his nervous system's reactions during two

physical and mental testing periods.

To assess the link between nervous system activity and HIV

progression, for 12 to 18 months the scientists also monitored each

man's HIV viral load and T-cells, which AIDS destroys.

During the evaluation period, some of the research subjects began

antiretroviral drug therapy. The researchers studied these men's

responses to the drugs by tracking their viral loads and T-cell

counts. A boost in T-cells shows recovery from HIV on antiretroviral

drugs.

" We found a strong linear relationship between personality and HIV

replication rate in the body, " Cole said. " Shy people with high

stress responses possessed higher viral loads. "

The researchers were surprised to find that the antiretroviral drugs

barely made a dent in the shy patients' disease. Instead of showing

lower viral loads, the immune systems of introverted subjects

replicated the virus between 10 to 100 times as fast as in other

patients.

" Shy patients on drug therapy didn't experience even a 10-fold drop

in their viral load, " said Naliboff, co-director of the UCLA Center

for Neurovisceral Sciences and Women's Health. " Doctors classify that

as a treatment failure. The drugs should shrink HIV replication by at

least 100 fold. "

" Our findings suggest that high nervous system activity helps the

virus continue replicating, " Cole said. " Patients with high-stress

personalities continued to lose T-cells -- even on the best drug

therapy available. Stress sabotages their battle against this lethal

disease. "

" It looks as though sensitive people are simply wired to respond to

stress more strongly than resilient people, " Naliboff said. " How

someone reacts to stress seems to be more important than the stress

itself in explaining why one person gets sick and one person

doesn't. "

" This heightened stress response is the equivalent of waves striking

a stone on the beach, " Cole said. " One wave won't do much damage. But

the constant pounding of waves eventually grinds that stone to sand.

That's how continual stress response wears down the immune system. "

Previously the UCLA team found that the body under stress releases a

chemical called norepinephrine that leaves the T-cells open to

infection and accelerates HIV replication. The researchers' next step

will be to try and change shy persons' physiologic response to stress

using drugs that block norepinephrine's impact on T-cells.

" Our current study suggests that the body's production of

norepinephrine during stress makes a big difference in people trying

to fight off infection, " Cole said.

Margaret Kemeny, Fahey and Jerome Zack co-authored the article.

The National Institute of Allergy and Infectious Diseases, UCLA

Center for AIDS Research, Universitywide AIDS Research Program, and

Veterans Affairs Medical Research funded the study.