Reactions to alcohol: cortisol clues.

Reactions to alcohol: Cortisol clues

The natural sons of alcoholic fathers are thought to be a group at great risk for developing alcoholism later in life. Recent studies indicate that a substantial portion of this group shares a brain wave deficiency with chronic alcoholics and reports feeling less drunk after a few drinks compared with controls who have no alcoholic relatives (SN: 9/29/84, p.196).

To these potential "markers' of a predisposition to alcoholism, researchers now add a hormonal measure: levels of cortisol in the blood stream. Marc A. Schuckit of the San Diego Veterans Administration Hospital and his colleagues find that this indirect measure of biological responsiveness to alcohol is lower after drinking among young adult sons of alcoholics than among sons of nonalcoholics.

The data suggest that sons of alcoholics have a less intense biological reaction to alcohol that promotes greater use of the substance, report the investigators in the November ARCHIVES OF GENERAL PSYCHIATRY. It is not yet clear, they say, whether differences in cortisol response to alcohol are genetically controlled or directly tied to an alcoholic predisposition.

The researchers chose cortisol as a biological measure because a number of human and animal studies have shown that blood levels of the hormone increase after fairly large doses of alcohol are ingested. Also, as tolerance to alcohol develops with continued drinking, cortisol levels do not drop off.

Schuckit and his co-workers tested 30 healthy, young adult sons of alcoholic fathers and 30 sons of nonalcoholics. Subjects in the two groups were matched for age, race, religion and educational level. Each received three types of drinks in random order: a placebo with no alcohol, a moderate dose of alcohol mixed in a sugar-free, noncaffeinated, carbonated beverage, and a heavy dose of alcohol in the same mixer.

Blood cortisol levels, measured every 30 minutes for four hours after each test, were significantly lower for sons of alcoholics in the two alcohol conditions, particularly following the heavy dose. A similar difference was observed 30 minutes after the placebo was administered, note the scientists, suggesting that, at least in the early going, reactions to lab procedures may have affected cortisol levels. But, they add, the largest group differences occurred about two hours after drinking alcohol, well past the 30-minute point.