People with depression generally have higher levels of glucocorticoids due to an overactive stress-response
Glucocorticoid levels are typically abnormal in people who are clinically depressed. A relatively infrequent subtype of depression, called “atypical depression,” is dominated by the psychomotor features of the disease—an incapacitating physical and psychological exhaustion. Just as is the case with chronic fatigue syndrome, atypical depression is characterized by lower than normal glucocorticoid levels. However, the far more common feature of depression is one of an overactive stress-response—somewhat of an overly activated sympathetic nervous system and, even more dramatically, elevated levels of glucocorticoids. This is probably worse for those who have experienced some for of childhood neglect, since a stressful childhood can result in an overactive stress response in later life. This adds to the picture that depressed people, sitting on the edge of their beds without the energy to get up, are actually vigilant and aroused, with a hormonal profile to match—but the battle is inside them.
Research stretching back some forty years has explored why, on a nuts-and-bolts level, glucocorticoid levels are often elevated in depression. The elevated levels appear to be due to too much of a stress signal from the brain, rather than the adrenal glands just getting some depressive glucocorticoid hiccup all on their own now and then. Moreover, the excessive secretion of glucocorticoids is due to what is called feedback resistance—in other words, the brain is less effective than it should be at shutting down glucocorticoid secretion. Normally, the levels of this hormone are tightly regulated—the brain senses circulating glucocorticoid levels, and if they get higher than desired (the “desired” level shifts depending on whether events are calm or stressful), the brain stops secreting glucocorticoids. Just like the regulation of water in a toilet bowl tank. In depressives, this feedback regulation fails—concentrations of circulating glucocorticoids that should shut down the system fail to do so, as the brain does not sense the feedback signal.
References
- Sapolsky, Robert. (2004). Why Zebras Don’t Get Ulcers Chapter 14. Stress and Depression (p. 416). New York, NY: Henry Holt and Company.
Metadata
Type:🔴 Tags: Biology / Neuroscience / Psychiatry Status:☀️