Study Finds Stress Hormone Plays Important Role in Alcohol Dependence
The study, led by Associate Professor Marisa Roberto of The Scripps Research Institute, also shows that CRF can be blocked on a long-term basis in rats to alleviate the symptoms of alcoholism.
Previous studies have suggested that CRF plays a role in alcohol dependence, but the effectiveness of blocking CRF was only shown in acute single doses of an antagonist (a substance that interferes with the action of another substance). This study used three different CRF antagonists, and all of them helped with alcohol dependence. Administering the antagonist for 23 days blocked increased drinking, which is associated with alcohol dependence.
Roberto, who won the 2010 Presidential Early Career Award for Scientists and Engineers, said that their study looked at the compulsion to drink—not because drinking is pleasurable, but because it relieves the anxiety that comes with withdrawal and abstinence.
CRF is a natural substance that plays a role in the body’s response to stress. It was originally thought to be located only in the hypothalamus, but has now been found in other brain regions, such as the pituitary and the amygdala, which has been associated with the stress, anxiety, withdrawal, and excessive drinking that comes with alcohol dependence.
Through a multidisciplinary approach, the researchers were able to confirm the role of CRF in the central amygdala. They also found that the effects of CRF could be blocked by administering CRF antagonists. Alcohol-dependent rats receiving one of the antagonists mimicked the non-addicted rats, self-administering alcohol in moderate amounts instead of seeking out large amounts of alcohol as untreated rats did.
The rats didn’t develop a tolerance to the antagonists, and actually became more sensitive to them over time.
Roberto added that the study also provides a possible link between disorders (such as stress, depression, and anxiety) and developing alcohol dependence.
Source: Science Daily, Stress Hormone Key to Alcohol Dependence Discovered, January 27, 2010