The casual link between stress and disease
There is compelling data suggesting a casual link between stress and conditions like cardiovascular disease, HIV/AIDS, and depression. Although this link has not been proven, researchers such as Sheldon Cohen, Ph. D., of Carnegie-Mellon University, are examining the reality. In a review centered on a paper delegated by the Institute of Medicine, Dr. Cohen wrote, “other areas in which evidence for the role of stress is beginning to emerge include upper respiratory tract infections, asthma, herpes viral infections, autoimmune diseases, and wound healing.” In general, a connection between stress and both mental and physical diseases has been observed. The difficulty in taking a closer look at this phenomenon is based in ethical concerns. It would not be ethical to subject human volunteers to testing that would induce stress that could potentially bring on disease. To date, researchers have been limited to studies based on responses to real-life stress. The following is an excerpt of an article from MedPageToday that discusses studies based on reactions to real-life stress:
Yet real-life evidence from studies looking at associations between stressful life events and disease reveal intriguing clues, the authors wrote.
For example, in some studies of major depressive disorder, 50% to 80% of patients reported a stressful event such as the death of a spouse in the months prior to the diagnosis.
“Although most investigations have focused on life events as triggers of depression onset, increased stress also predicts the clinical course of major depression, including features such as longer duration, symptom exacerbation, and relapse,” they wrote. “Evidence also suggests that events that occur concurrently with treatment reduce positive response.”
Similarly, work with animal models and observation of healthy adults and cardiac disease patients point to an association between stress and myocardial ischemia, and activation of both inflammatory and coagulatory mechanisms, they wrote.
In addition, prospective studies have found strong associations between psychological stress and cardiovascular disease morbidity and mortality.
The evidence for a link between stress and HIV/AIDs comes from studies detecting a link between stress from cumulative negative life events and HIV progression, they noted.
“For example, among HIV-positive men, each additional moderately severe event increased the risk of progressing to AIDS by 50% and of developing an AIDS-related clinical condition by 2.5-fold,” the authors wrote. “Moreover, stress has been found to influence the course of virally initiated illnesses to which persons with HIV are especially susceptible. These studies are supported by experimental research with animals wherein exposure to social stressors results in decreased survival.”