Does Stress Cause Disease? It Doesn't Help, Reviewers Say

[~MaryO~]

http://www.medpagetoday.com/Psychiatry/AnxietyStress/tb/6926

 

Does Stress Cause Disease? It Doesn't Help, Reviewers Say

 

 

By Neil Osterweil, Senior Associate Editor, MedPage Today

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

October 10, 2007

 

MedPage Today Action Points

• Explain to patients that psychological stress is known to have deleterious effects on health, and may lead to unhealthy behaviors such as smoking, over-eating, and drug or alcohol abuse.
  

Review

 

PITTSBURGH, Oct. 10 -- There is strong evidence suggesting -- but not proving -- the existence of a causal link between psychological stress and chronic conditions such as depression, cardiovascular disease, and HIV/AIDS, asserted researchers here.

 

"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," wrote Sheldon Cohen, Ph.D., of Carnegie-Mellon University, in today's issue of the Journal of the American Medical Association.

 

In their review article, based on a paper commissioned by the Institute of Medicine, the authors examined evidence linking stress to chronic diseases by two essential pathways: the hypothalamic-pituitary-adrenocortical axis (HPA) and the sympathetic-adrenal-medullary system.

 

"Cortisol, the primary effector of HPA activation in humans, regulates a broad range of physiological processes, including anti-inflammatory responses; metabolism of carbohydrates, fats, and proteins; and gluconeogenesis," they wrote.

 

"Similarly," they said, "catecholamines, which are released in response to sympathetic-adrenal-medullary activation, work in concert with the autonomic nervous system to exert regulatory effects on the cardiovascular, pulmonary, hepatic, skeletal muscle, and immune systems."

 

Chronic or repeated activation of these systems through stress could lead to increased risk for both mental and physical disorders by interfering with the ability of those systems to control other physiological processes, the authors wrote.

 

They noted that stress can increase the risk for cardiovascular disease by impairing vagal tone, and that it can effect the regulation of immune and inflammatory processes, with a potential for contributing to depression, infectious diseases, autoimmune conditions, coronary artery disease, and some cancers, such as those that are virally mediated (cervical cancer, for example).

 

"Psychological stress might alter immune function through direct innervation of lymphatic tissue, through release of HPA and sympathetic-adrenal-medullary hormones that bind to and alter the functions of immunologically active cells, or through stress-induced behavioral changes such as increased smoking," they suggested.

 

But the question of whether stress actually causes diseases is a trickier one to answer, they suggest, noting that it would be unethical to subject human volunteers to stress to see whether it could cause serious disease.

 

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."

 

The evidence for the effect of stress on cancer in its earlier stages is shakier however, although tumors with a viral influence, such as cervical adenocarcinomas or hepatocarcinomas, may be exacerbated by the immune-dampening effects of stress, the authors suggested.

 

"Evidence derived from prospective observational studies provides support for stress as an important factor in certain diseases but cannot establish a causal relationship," the authors wrote.

 

"However," they noted, "the results of these studies are consistent with those of natural experiments regarding the effects of real-life stressor exposure on disease risk; with those of laboratory experiments showing that stress modifies disease-relevant biological processes in humans; and with those of animal studies investigating stress as a causative factor in disease onset and progression. This consistency of research findings strongly supports the hypothesis of a causal link."

 

Dr. Cohen reported consulting for Johnson & Johnson Consumer Companies on issues of stress measurement. The Institute of Medicine Committee on Psychosocial Services to Cancer Patients and Families in Community Settings commissioned the paper on which the article is based.

 

Primary source: Journal of the American Medical Association

Source reference:

Cohen S et al. "Psychological Stress and Disease." JAMA 2007; 298(14): 1685-1687.

[fallerb]

The thing that this says most strongly to me is that early diagnosis and treatment of Cushings is critical.

[judycolby]

I have a few thoughts on stress & chronic illness. Bear with me, it may take awhile

 

Okay, you all know I have Crohn's and have for many years so I have a LOT of experience reading my body. I have found that before a flareup I get very depressed. Now one doctor has suggested to me that the depressin caused the flareup. But when my meds were adjusted after I started showing physical symptoms my depression would go away. And none of those meds were anti depressants.

 

During the time from when the depression began until a few days after the meds were adjusted life was just very stressful. Almost toooverwhelming to manage.

 

For example during one of these periods the passenger door handle on the van broke, it couldn't be opened from the outside. My sister was going with me to a doctor appointment in a few days and it REALLY stressed me that the door didn't open and I spent two days trying to get it figured out. Now,many months later after being ondecent meds and Croh's is in remission the exact same thing happens again, same door. I laughed and said well that didn't last long. The same week I had to take the cat to the vet and several other thngs that don't normally happen within a one week period. Probably a couple of appointments for Justin with a doctor or something.

 

Nothing phased me as long as my body was feeling okay. And quite often that overwhelming feeling came way before I had any physical symptoms. ANYTHING out of synch was stressful then. Even forgetting to thaw out meat for supper. And I'm the queen with frozen meat, usually.

 

I remember years ago having two very easy going customers at work that we saw at least weekly. Then one day they came in crabby and stayed that way. Many months later they were each diagnosed with heart problems. We'd been saying to each other for a long time that they needed to go to the doctor because something was wrong.

 

I think there's a good chance, at least in alot of cases that the body already has a problem that has not been discovered, causing alot of stress, and the symptoms are sublte enough that they go undetected for a while,

then later a diagnosis of "something" is made & it is believed that the stress caused the physical symptoms.

I think the physical problems were already there and they caused the stress.

 

Am I making any sense? I talked to my GI about it one time and he thought it sounded like a good theory but not good enough to change my meds based on depression & stress alone. Have to wait for those physical symptoms. He said you've really thought about it, I said well, I live it.

 

I wouldn't say this is always the case but I would bet money that it is quite often. In fact I told my boss it I had any idea how to go about it, I'd apply for a grant & study it.

 

Just my thoughts on the subject. I'm not sure anyone that didn't live with a disease could ever put that together.

 

Judy