- Cortisol, a "stress hormone," plays an important role in the regulation of emotion, cognition, reward, immune functioning, and energy utilization.
- New research has found that long-term chronic drinking produces an increase in cortisol both during intoxication and withdrawal.
- Cortisol appears to increase significantly during the progression from chronic intoxication to withdrawal..
Cortisol, known as a "stress hormone," plays an important role in the regulation of emotion, cognition, reward, immune functioning, and energy utilization. A study published in the September issue of Alcoholism: Clinical & Experimental Research has found that long-term chronic drinking produces an increase in cortisol both during intoxication and withdrawal.
"It has not been known whether the body adapts to the stress of drinking following daily heavy drinking in the non-laboratory setting, or whether cortisol levels continue to be elevated even after several weeks or months of drinking," said Bryon H. Adinoff, Distinguished Professor in the department of psychiatry at the University of Texas Southwestern Medical Center at Dallas, medical director of the Substance Abuse Team at the Veterans Affairs North Texas Health Care System in Dallas, and first author of the study. "In this study, we show that even persons drinking for several months continue to show elevated levels of cortisol. In addition, levels of cortisol increase even further when the drinking stops. This increase occurs even before alcohol is gone from the body. The daily, heavy drinker may therefore have levels of cortisol two to three times the normal amount throughout the day and night."
Cortisol is the primary glucocorticoid in humans. Glucocorticoids are produced by the adrenal glands, two thumb-size organs that lie behind both kidneys. When a body's stress-response system is activated by stressors, usually unpredictable or fear- and/or anxiety-causing in nature, cortisol is increased. Stress-induced cortisol can focus alertness and attention, increase blood pressure, and suppress 'less necessary' bodily functions such as wound repair, bone growth, digestion, and reproduction.
"Alcohol can increase cortisol through a variety of mechanisms," said Adinoff. "Alcohol directly affects many brain chemicals that signal the adrenal glands to produce and secrete cortisol. High levels of intoxication may be interpreted as general 'stress,' which could stimulate cortisol release. Finally, after drinking a lot of alcohol for a long time, the sudden stopping of drinking can produce a stressful 'withdrawal' state, which can also increase cortisol production."
For this study, researchers examined salivary cortisol levels and breath alcohol concentrations in two groups of males: 73 alcohol-dependent patients presenting themselves for treatment in an intoxicated, withdrawal, or post-withdrawal state; and 22 abstinent alcohol-dependent patients already enrolled in a residential treatment program.
"The usual method of obtaining cortisol levels is by obtaining a blood sample," said Adinoff: "However, it is much easier for both the patient and researcher to obtain a sample of saliva rather than a blood sample …and less painful for the patient."
Salivary cortisol is also a better measure of active cortisol. When cortisol is in the blood, it is in two forms, "bound" and "unbound." Bound cortisol is not active because it is attached to a protein. Only the unbound, or free, cortisol is physiologically active. Most of the cortisol in blood is bound. Conversely, all of the cortisol in saliva is unbound, free, or active. Therefore, saliva measures of cortisol give a better picture of how much active cortisol is in the body.
Study authors found that cortisol concentrations in alcohol-dependent individuals increase during both intoxication and withdrawal, compared to abstinence. Of the 73 alcohol-dependent patients presenting themselves for treatment, 38 were intoxicated. These 38 individuals, as well as 30 non-intoxicated individuals going through acute alcohol withdrawal, had significantly increased salivary cortisol concentrations when compared to abstinent individuals. Furthermore, cortisol concentrations increased during the progression from intoxication to withdrawal.
"Up until now, it is has not been known whether cortisol remains elevated in chronic drinkers not in a laboratory setting," said Adinoff. "The confirmation that cortisol does, indeed, remain elevated throughout the drinking cycle suggests that it may be important to decrease cortisol levels during both chronic drinking and withdrawal. This suggestion is tentative, however, as it has not yet been shown that it is cortisol itself that is responsible for the medical and psychiatric problems associated with heavy drinking. Future studies should explore the relationship between elevated levels of cortisol during intoxication and withdrawal and the medical and psychiatric consequences of drinking, which may include sleep disruption, cognitive deficits, diabetes, and mood disturbances."
Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper included: Keith Ruether and Mark J. Williams of the Department of Psychiatry at the University of Texas Southwestern Medical Center in Dallas; Steven Krebaum of the Veterans Affairs North Texas Health Care System in Dallas; and Ali Iranmanesh of the Department of Medicine at the University of Virginia in Charlottesville, and the Veterans Affairs Medical Center in Salem, both in Virginia. The study was funded by the National Institute on Alcohol Abuse and Alcoholism.