Why is depression twice as common in women compared to men? Despite many years of academic study, the answer remains uncertain. But a team of eight researchers at the Children’s Hospital in Philadelphia have now identified the chemical that causes the apparently greater stress sensitivity in women. The study, which involved male and female lab rats, revealed that this chemical behaves differently in females than in males. The researchers are confident that the results of this study can lead to more effective treatments for all types of stress-related illnesses.
This study provides the first hard evidence for gender differences at the level of CRF receptors. CRF (Corticotropin-Releasing Factor) is a neuropeptide – a protein molecule secreted by nerve cells. Its job is to activate the body’s automatic response to stressful external situations.
Released in normal doses, CRF helps neurons communicate with each other, in order to send messages throughout the body. Those who are unable to adapt to high levels of CRF are more likely to develop various stress-related psychiatric disorders like depression or Post-Traumatic-Stress Syndrome. These disorders are marked by symptoms that often include anhedonia, panic attacks, sleep disturbances and impaired ability to concentrate. Stress can be loosely described as a psychological reaction to challenging events that threaten or exceed our ability to cope with them.
With the help of an electron microscope, researchers studied the brain cells of male and female rats, after the experimental procedure was completed. The results of the study revealed gender differences in CRF signaling. In other words, the female rats showed higher levels of stress-induced CRF. Even in an unstressed state, the females showed a more intensified response to the activation of CRF in their systems. Over time, females also showed a decreased ability to adapt to excessive doses of CRF.
The findings also suggest that these gender differences are the result of the organizational effects of testosterone during critical periods of human development. The function of CRF may well underlie the greater vulnerability of women to clinical stress-related disorders. Researchers are hopeful regarding the development of treatments they call “CRF antagonists.” These are expected to be particularly helpful in treating the kinds of psychiatric afflictions known to be more common among women than men.