Meet a Member of NACCAM
Sheldon Cohen, Ph.D.
"Volunteers who reported greater stress in their lives were more likely…to develop a cold."
— Dr. Sheldon Cohen
Sheldon Cohen, Ph.D., is a member of NCCAM's National Advisory Council for Complementary and Alternative Medicine (NACCAM). He is the Robert E. Doherty Professor of Psychology at Carnegie Mellon University, Pittsburgh; an adjunct professor of pathology and psychiatry at the University of Pittsburgh School of Medicine; and a member of the Pittsburgh Cancer Institute. His research focuses on the effects of psychological stress, mood, interpersonal relations, social status, and childhood experiences on health and well-being. Dr. Cohen received his Ph.D. in psychology from New York University. He is a member of the Institute of Medicine of The National Academies.
In several studies, your team evaluated the stress levels in each member of a group of volunteers. Then you injected them with a cold virus and observed whether they came down with a cold. What did you find out?
When exposed to a common-cold virus, the volunteers who reported greater stress in their lives were more likely than those with less stress to develop a cold. This association has held across eight different upper-respiratory viruses that we have tested.
Why do you think this has happened?
Our immune system responds to viral infections by releasing pro-inflammatory cytokines—protein molecules that help coordinate the immune response. However, when we produce these cytokines above the level needed to fight the infection, they also trigger cold symptoms, such as a runny nose or congestion. People who report greater levels of stress produce many more of these pro-inflammatory cytokines than those who have less stress.
What are some other factors you have found that appear to be connected to our chances of getting a cold?
Certain stressful life events that are chronic and enduring appear to have a connection, such as poor marriages and unsatisfying jobs. So do stressors that come from enduring social conflicts. Happy, enthusiastic people are less susceptible to colds. People who are outgoing (i.e., extraverts) and/or have diverse social networks (such as friends, family, close neighbors, and coworkers) are also less susceptible, even after we account for the protective effect of the extra immunity they may gain from increased contact with other people.
Positive emotions and social networks could help make us less susceptible to colds.
© iStockphoto.com/digitalskillet
Social economic status (SES, made up of factors like income, education, and occupational status) also appears to play a part. When we objectively measured participants' SES, we did not find it to be connected with their chances of getting a cold. However, we did find a connection when it came to perceptions of SES. Those who perceived their SES as being lower than other people's were more susceptible to colds. Our most recent work suggests that if you have low SES during early childhood, you will be more susceptible to colds as an adult, regardless of your SES.
Do you think your findings may have implications for our susceptibility to other infectious diseases, not just colds?
As we better understand the biology of how psychological and social factors influence cold susceptibility, we will be more able to extend these findings to other diseases. If it turns out, for example, that regulation of pro-inflammatory cytokines is the real culprit, then other diseases involving an excess of these cytokines (the inflammatory diseases) are likely to show the same type of effects.
What is the most important thing you do on NACCAM?
I think probably the most important role of the Council is to provide feedback and guidance regarding research directions the Center is considering.
Selected References
Cohen S, Doyle WJ, Skoner DP, et al. Social ties and susceptibility to the common cold. Journal of the American Medical Association. 1997;277(24):1940–1944.
Cohen S, Doyle WJ, Turner R, et al. Childhood socioeconomic status and host resistance to infectious illness in adulthood. Psychosomatic Medicine. 2004;66(4):553–558.
Cohen S, Janicki-Deverts D, Miller GE. Psychological stress and disease. Journal of the American Medical Association. 2007;298(14):1685–1687.
Cohen S, Tyrrell DA, Smith AP. Psychological stress and susceptibility to the common cold. New England Journal of Medicine. 1991;325(9): 606–612.
