The Queensland Institute of Medical Research (QIMR) and the Royal Prince Alfred Hospital have determined that although alcohol consumption and alcohol dependence are closely related, the causes of susceptibility are not necessarily the same.
This new study found that variation in long-term average alcohol intake is almost entirely due to genetic differences.
A study in the August issue of Alcoholism: Clinical & Experimental Research looks at genetic and environmental causes of variation in long-term alcohol consumption, and estimates what degree of overlap may exist with causes of susceptibility to alcohol dependence. Results indicate that variation in long-term average alcohol intake is almost entirely due to genetic differences, and that some genes affect both intake and dependence while others affect only dependence.
"Alcohol consumption is about how much a person drinks at some particular time, whereas alcohol dependence is more about the effects of alcohol on a person - their behaviour, their neurophysiology, and their relationships," said John Whitfield, first author of the study and senior scientist at the RPA Hospital and part-time QIMR research fellow. "Most people in western societies consume alcohol but only some consume it in large enough quantities to cause harm," said Whitfield, "similarly, only some are so affected by it that they meet the psychiatric criteria for 'alcohol dependence.' There may not be a relationship between intake and dependence, except during bouts of uncontrolled and extremely heavy drinking, or there may be some overlap or common causes for each, or the same underlying causes for both. The study sought to explore this relationship, which has received little attention in the past because most studies have concentrated on either one or the other."