Mark Dombeck, Ph.D. was Director of Mental Help Net from 1999 to 2011. Dr. Dombeck received his Ph.D. in Clinical Psychology in 1995 ...Read More
The April issue of Behavioral Neuroscience contains a report generated by two boston based scientists who have established the hormonal basis by which chronic stress causes anxiety and depression (actual journal article here). It has been known for many years that chronic stress is associated with a variety of mental and physical symptoms, amoung them anxiety and depression. It has also been known for years that the hormone Cortisol is associated with the stress response, and that many depressed people have elevated Cortisol levels. What has apparently not been known with any certainty until just now, is whether Cortisol is a cause of anxiety and depression, or a mere side effect. After all, it is pretty stressful to be depressed and anxious.
The only way to tease apart whether Cortisol is a cause or an effect of anxiety and depression is to see if it is possible to induce anxiety and/or depression by exposing people to Cortisol. For a variety of ethical reasons, the politically correct way to do this sort of thing is to work with animal subjects rather than human beings. The researchers thus did a rat study, putting the rat equivalent of Cortisol into rat’s drinking water for varying amounts of time, and watching how they behaved as a result. Rats who were only exposed to the Cortisol analog for a short time showed no discernable effects. However, rats who got the Cortisol for two or more weeks acted anxious and depressed:
"Compared with mice given stress hormone for a day, mice given stress hormone for more than two weeks took significantly longer to emerge from a small dark compartment into a brightly lit open field, a common behavioral test of anxiety in animals. In other words, they seemed more fearful and were less willing to explore the new environment. Chronic but not acute treatment also dulled reactions to a startling stimulus, another sign their nervous systems were overwhelmed."
It is certainly not terribly shocking news that Cortisol causes symptoms of anxiety and depression, but this is legitimate science, nevertheless. Most science is not terribly sexy. Sometimes science is sometimes about discovering new exciting things, but more often, it is about verifying assumptions – crossing Ts and dotting Is and filling in the blanks. Verification efforts like this one serve science’s ultimate goal and reason-for-being which is to help us better predict and control the world. Prediction and control cannot happen with any certainty when knowledge is based on assumptions. I always liked the way that Felix Unger (the uptight character from the old TV show "The Odd Couple") put it: "When you ASSUME things, you make an Ass of U and Me".