Think Positive

Many studies have shown that a person's emotional state may affect his or her physical health. Depression can worsen heart disease, and stress may contribute to colds.

Scientists at the University of Wisconsin have shown that people with high activity in a particular brain area may muster weak immune responses in the face of negative emotions.

Melissa Rosenkranz and colleagues monitored the brain activity of 52 men and women and asked them to write about emotionally negative moments in their lives. Researchers then injected each subject with a flu shot and tracked the level of antibodies in their blood to discover how well their bodies were fighting the virus in the vaccine. They found that subjects with high electrical activity in the right prefrontal cortex during the emotional writing task produced lower levels of antibodies, indicative of impaired immunity.

Rosenkranz says the study is the first step toward discovering a neural mechanism explaining the mind's effect on the body. The
study was published in the Proceedings of the National Academy of Sciences.