Endocrinologist Stafford Lightman
Chronic Stress Can Significantly Damage Health (cont'd)
Q: When does the stress response become dangerous?
A: The important thing about the stress response is it's adapted for short-term responses. It becomes dangerous when you get multiple stress responses, one after the other, or experience chronic stress that goes on for weeks or years. When that happens your levels of cortisol can be raised for very prolonged periods of time, and it can have lots of nasty effects on the body. It can damp down your immune system, for instance, so that you can't respond to diseases as well as you should. It can also have effects on the brain, actually decreasing the number of brain cells in certain parts of the brain and decreasing your memory. It also can affect your blood pressure, and it can affect the fats in the blood and make it more likely for you to have heart attacks and strokes. So when you have chronic stress, that's when stress becomes dangerous.
Q: Can caring for people with chronic illnesses actually lead to illnesses in caregivers?
A: There's been quite a lot of interest recently about what chronic stress can do to cause disease. We did a study on caregivers of patients with Alzheimer's disease…We've looked at their hormones and we find that their cortisol is indeed raised, so they have a hormonal stress response which is prolonged for a very long period of time. We've also looked at their immune function by giving them influenza vaccination, which is routinely given to elderly people, and we've found that their antibody response to the influenza vaccination is much poorer than equivalent people of the same age who aren't caring for a loved one with Alzheimer's or some other disease.
So it's clear that chronic stress does damp down the immune system. And other people have also shown that chronic stress can decrease your ability to heal wounds, so that if you've got small wounds they just don't heal as well. The body just doesn't function quite as well when you have large, high levels of cortisol circulating through it for long periods of time.
Q: Has stress been linked to depression and other mental illnesses?
A: It's quite clear that chronic stress is related with depression. Depression is a very major common disease in our society, and it is undoubtedly related to the chronic stress that we have in our society.
The ability of stress to cause depression as well as other problems like heart disease and high blood pressure are connected in an interesting way. [Patients who are depressed after a] heart attack are much more likely to die within the next few years than people who've had heart attacks and who aren't depressed. So again this depression, which is related to chronic stress, actually has a major effect on life expectancy.
Q: Might there someday be a pill to reduce the effects of stress?
A: We are involved in an intensive program to develop an anti-stress pill, and the only way we can do this really is to try and block the beginning of the pathway in the brain that causes the response to stress. And this happens at the hypothalamus, which makes a hormone called CRH. We're making a pill that blocks the effect of CRH, and therefore blocks all of the effects of stress on the body, including the effects of stress in causing an increase in cortisol. We're not designing a drug to give to everybody who's stressed. But this can be very important and hopefully should actually be an extremely useful treatment for … depression that's associated with severe stress.
