Fish research finds link between chronic stress, depression
Effexor users who have suspected that chronic stress is a cause of their depression may be right.
Effexor users who have suspected that chronic stress is a cause of their depression may be right. Researchers at the Max Planck Institute of Neurobiology have recently found a link between high levels of stress hormones and anxious or depressed behavior in zebra fish.
In the study, published in the June 2013 edition of Molecular Psychiatry, researchers analyzed fish that lacked the glucocorticoid receptor, which regulates cortisol. When the hormone cortisol is released in high levels, it causes consistently elevated stress in humans and other animals. When placed in a new tank, the zebra fish with this genetic mutation showed extreme signs of depression and hyper-anxious behavior, such as sinking to the bottom of the tank and freezing. Typically, fish can appear a bit nervous when entering a new habitat, but they acclimate fairly quickly. The fish in this study took an excessively long time to adjust and, when tested, they had elevated concentrations of cortisol, CRH and CTH - all of which are stress hormones.
However, shortly after scientists added an antidepressant to the water, the behavior of the fish returned to normal. This is an important finding because it establishes a causal link between the malfunction or lack of a glucocorticoid receptor, elevated stress hormones and depression and anxiety. While researchers are not able to establish a causal link in human research, they can say that chronic stress is associated with depression. Additionally, the zebra fish research can provide insight into how antidepressants or anti-anxiety medications can work to reduce stress levels.