Sons of Alcoholic Fathers Poor Judges of When They've Had Enough to Drink
A "hollow leg" in a young man with a family history of alcoholism may be a sign 
of trouble down the road.
That was a principal finding in an eight-year follow-up of 450 sons of alcoholic 
fathers and control subjects by Marc A. Schuckit, M.D., a professor of 
psychiatry at the San Diego V.A. Hospital and the University of California, San 
Diego, and Tom L. Smith, Ph.D., published in the Archives of General Psychiatry 
last month.
The study found that a low level of response to alcohol at around age 20--the 
ability to drink alcohol without feeling strong effects--appears to be a 
powerful predictor of later alcoholism and may serve as a "mediating factor" in 
those individuals who have a family history of alcoholism.
"If you have a hollow leg at age 20, you have a much higher risk of alcoholism," 
Schuckit said in an interview. "This factor is a fairly strong predictor. 
"This low level of response appears also to be genetically influenced and runs 
strongly in families," he added. "Putting the two together, if you have a low 
response to alcohol in your late teens and you have a family history of 
alcoholism, your risk for alcoholism by age 30 is about 60 percent."
Schuckit noted that the population in his study was predominantly 
high-functioning white males, most of whom were college students.
Among this group, the power of the "level of response" (LR) to alcohol was 
consistent regardless of whether the young men were heavy drinkers or light 
drinkers in their teens; if they had a low level of response to alcohol, by age 
30 they were still more likely to have developed alcoholism.
Schuckit also noted that in this sample the two factors under study--family 
history and level of response to alcohol--were not predictive of other 
psychiatric disorders.
The finding suggests that, among this population at least, alcoholism did not 
result as a function of "self-medicating" underlying psychiatric disorders, 
Schuckit said; the level of response alone appears to be the influential factor.
The power of LR in determining the outcome of young men with a family history of 
alcoholism is extraordinary, according to Schuckit's findings: in the 
statistical analysis of results, the effect of family history on later 
development of alcoholism diminishes when LR is removed as a factor.
But the risk for later development of alcoholism drops hardly at all when the 
effect of family history is dropped and only LR is considered, Schuckit said.
The rates of development of DSM-III-R abuse and dependence on alcohol were 14.1 
percent and 28.6 percent, respectively, for men with a family history of 
alcoholism, compared with 6.6 percent and 10.8 percent, respectively, for men 
with no family history of alcoholism.
"[A] positive family history of alcoholism was associated with an almost 
threefold increased risk for alcohol abuse or dependence in the sons of 
alcoholic fathers, even though the original sample was composed of relatively 
high-functioning blue- and white-collar men," Schuckit and Smith write in the 
Archives article.
Among these men with an increased risk for alcoholism due to family history, the 
level of response to alcohol may be the decisive mediating variable, the 
investigators say.
But they note that even this highly discrete variable is likely to act in 
concert with other moderating and mediating variables. 
Further study of men with and without a low level of response to alcohol will 
help to ferret out those environmental factors that may interact with LR to 
produce alcoholism, they say.
"[T]he next stage in the follow-up of these 450 men to be carried out from 1994 
to 1999 is focusing on those individuals who did not experience alcohol abuse 
and dependence despite low levels of response to alcohol," Schuckit and Smith 
write. "Of equal interest will be subjects who experienced alcoholism despite 
relatively high sensitivities to the alcohol challenge. Such evaluations might 
help to identify psychologic and environmental influences that interact with 
family history and responsivity to alcohol to produce the risk for alcoholism. 
These factors to be studied include more detailed evaluations of the 
expectations of the effects of alcohol, styles of coping with stress, levels of 
life stress, social support systems, and several personality attributes."
(Psychiatric News, May 3, 1996)