The physiology of stress: Stress R Us by Dr. Greeley Miklashek
PIC member and retired neuropsychiatrist Dr. Greeley (Gregg) Miklashek has studied stress in humans. Over a 42-year practice, he helped 25,000 patients. Dr. Miklashek believes that stress is the common underlying factor in many “diseases of civilization.” To evaluate stress, he used his patients’ subjective anxiety assessments in conjunction with measuring their blood levels of the hormone cortisol, which is released from the outer part of the adrenal gland known as the adrenal cortex. Cortisol plays an important role in regulating circadian rhythms and the release of stored carbohydrates and fats for energy. However, during prolonged stress conditions, cortisol levels become chronically and detrimentally elevated. [The adrenal gland is much more widely known for the adrenalin it releases in “fight-or-flight” situations of immediate danger; that hormone is produced in its the inner part, or medulla.]
Pioneering stress researcher Hans Selye found that experimentally stressed animals developed enlarged adrenal glands, an involuted thymus and lymph nodes, and peptic ulcers. He described this stress response as “general adaptation syndrome” (GAS). The diseases that befell these intentionally stressed animals were similar to the “diseases of civilization” that afflict people in Western societies. John J. Christian, a contemporary animal crowding researcher of John Calhoun, suggested that adrenal glucocorticoids (cortisol is the major glucocorticoid in humans) were responsible for the population cycles (peaks and die-offs) in mammals.
Dr. Miklashek and his patients came to see that the patients’ psychiatric conditions fell within the spectrum of the common “diseases of civilization” that are the main killers in Western societies but almost unknown in hunter-gatherer societies and pastoral populations. Cortisol was the core health problem directly causing or indirectly making people vulnerable to the deadly diseases of modern “stressed-out” humans. Gregg uses the term COASTER as an acronym for “chronically over-active stress response.” The diseases caused or facilitated by COASTER include essential hypertension, heart attacks and strokes; abdominal obesity and type 2 diabetes; suppressed immune function and the resultant increased vulnerability to all infections; anxiety, depression and suicide; addiction and other obsessive-compulsive disorders; kidney disease; thyroid disease; peptic ulcers and inflammatory gut diseases; cancers; and infertility. Today, 55% of American adults and 80% of those over 50 have at least one chronic health problem.
How does all this happen? Under normal conditions, cortisol levels have a daily cycle. They are low most of the day, but begin to rise early in the morning with a peak at awakening, followed by a rapid mid-morning decline. A continuously stressful situation results in persistently elevated levels of cortisol (i.e., COASTER). High levels of cortisol destroy lymphocytes (which make antibodies, thereby disrupting immune function which has many consequences), suppresses the production of gonadotropin-releasing hormones in the hypothalamus (which impairs reproduction), supresses the production of thyroid stimulating hormone from the pituitary (which lowers the level of thyroid hormones with widespread metabolic effects), causes hypertension, and has other physiological effects.
Gregg developed the concept of “population density stress” promoting disease in human populations. As well as being much more crowded, many of us have lost our connection to an extended clan beyond the nuclear family and to the natural world. There is also the phenomenon of “stress addiction” as stress releases endorphins, dopamine and other feel-good substances. High stress levels can also lead to substance use disorders to numb feelings of anxiety and depression. An extended period of high stress can lead to “adrenal fatigue” in which the adrenal glands cease to function. While too much cortisol suppresses immune function, with too little cortisol the immune system gets out of control and can attack normal organs and tissues, leading to auto-immune conditions. In addition, the release of stored energy is impeded. Affected individuals have been described as suffering from “chronic fatigue syndrome,” “nervous exhaustion,” or “neurasthenia.”