Study finds link between emotions, immune system
Shy men have much less resistance to the AIDS virus than extroverted men and benefit far less from treatment with antiretroviral drugs, according to a UCLA study.
Paying attention to the emotional state of patients with infectious and chronic diseases is increasingly becoming an essential part of treatment.
Although the connection between emotion and disease has long been suspected -- physicians as early as the 2d century AD observed a link between "melancholy" and physical illness -- researchers are now pinpointing networks of biological systems that connect temperament with the progression of illness.
In the new study, HIV-infected men who were introverted, reserved, and kept to themselves had nearly eight times as many viral particles in their blood compared with outgoing men. After treatment with antiretroviral drugs for as many as 18 months, the viral load among extroverted men fell 162-fold, said lead author Steve Cole at the AIDS Institute of the University of California at Los Angeles. Among shy men, the drop was only 20-fold.
"There is a link between psychological profile and poorer response to HIV, and maybe even a number of other viral diseases," agreed Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, the federal government's lead research center in the fight against AIDS.
Other research has shown similar connections between mental disorders such as depression and AIDS, osteoporosis, and cancer. A study of 5,000 people with depression showed they had twice the risk of developing cancer compared with people without the mental disorder, said David Spiegel, a professor of psychiatry at Stanford University School of Medicine.
And Philip Gold, chief of the clinical neuroendocrinology branch at the National Institute of Mental Health, found that pre-menopausal women who were depressed had a higher rate of bone loss and a two- to three-fold higher risk of osteoporosis compared with other women.
The UCLA study, published last month in the journal Biological Psychiatry, offered clues into the physiological pathways through which stress influences the body.
"People who have the shy, sensitive temperament seem to be more prone to having sympathetic nervous system responses," Cole said in an interview, referring to the part of the nervous system that causes accelerated heart rate and other unconscious changes. "They are more stressed by lots of things, including contact with unfamiliar people."
Gold said an important conclusion is that people with emotional disorders should be regularly monitored for osteoporosis and heart disease. And treating mental disorders, he said, could be a step toward slowing -- even preventing -- diseases such as AIDS.
