by Redford Williams, MD, and Virginia Williams, PhD
Hostility isn't the only negative trait that can have an impact on people's health. Behavioral medicine research has identified a number of other risk factors with a definite link to serious health problems.
Depression. The negative impact of depression also increases the risk of developing coronary heart disease, and people who are depressed after having a heart attack are more likely to die within the following 6 months. Several studies have shown that patients with any disease -- diabetes is one example -- who are depressed end up needing more medical care, accounting for a disproportionate amount of medical costs.
Lack of adequate social support. People who have little support -- whether it's help with chores at home or someone to listen sympathetically -- are also more at risk. Social support acts as a buffer that enables people to cope better with whatever stresses they face, whether they're imposed by personality or life situations. Support is a function of both the person and the environment. Those of us who have a cynical mistrust of others are less likely to reach out for support, and some of us find ourselves in situations that simply don't include people who can be sources of support.
Stressful environments. Jobs that impose high demands for output of services or products but allow workers little control over how those demands are met have been termed high-strain jobs. Psychologists Robert Karasek, PhD, of the University of Massachusetts, and Tores Theorell, MD, PhD, of the Karolinska Institute in Stockholm, Sweden, have documented that people working in high-strain jobs are more likely to develop high blood pressure, infections, and job-related injuries, as well as heart disease.
Risky behaviors. People who are hostile, depressed, isolated, or in stressful life situations are more likely to overeat, smoke, and abuse alcohol.
Studies show that these different risk factors often cluster in the same individual. For example, in a study of working women, Redford and his colleagues found that those who reported high job strain were also more depressed, hostile, and socially isolated. As in people with high levels of hostility, these other psychosocial risk factors are associated with changes in biological functions, such as increases in adrenaline and cortisol, blood pressure and heart rate surges, higher cholesterol levels, and alterations in the immune system and blood-clotting mechanisms. All of these changes are felt to lead to disease.
Redford's research has continued to build upon the observation that these risk factors, along with the accompanying biological markers of stress and health-damaging behaviors, tend to cluster among certain groups. The people most likely to be affected are those stressed by lower income, education, and/or occupational levels. This clustering may be the result of reduced brain levels of the chemical serotonin, a neurotransmitter that nerves use to relay messages to one another. When serotonin levels are low, we are more likely to be angry, depressed, and anxious; to be less interested in relating to other people; to have greater fight-or-flight responses when stressed; and to smoke, drink, and eat more than is good for us. If true, this theory could point to the brain's serotonin system as a key neurobiological mechanism that regulates our ability to be in control. Two studies have found weaker brain serotonin function in persons with lower income and education levels.
In his most recent research, Redford has begun to study how genes that are involved in regulation of serotonin affect all of these health-damaging psychosocial, biological, and behavioral characteristics. This work is still in an early stage, but we have some likely hypotheses for where it will go. The serotonin "transporter" is a molecule that sits on the surface of serotonin nerve end. It's responsible for the reuptake of serotonin -- squelching the effects of the neurotransmitter after it's been released from the nerve endings. The gene responsible for making this transporter comes in various forms. Certain of these forms seem to make a person more likely to experience negative emotions, such as anger and depression, and to have greater adrenaline, blood pressure, and heart rate surges when angered.
Redford's ongoing work aims to identify the interactions between key genes and the environment and to help account for the clustering of health-damaging characteristics in the same individuals and groups. No doubt, we'll also learn more about how genes affect our ability to be in control in stressful situations. Stay tuned for additional revealing research, but in the meantime, let's talk about how you fit in to this picture.
Copyright © 2006 Redford Williams, MD, and Virginia Williams, PhD