Parental alcoholism carries risk for offspring to develop the same, population-based study confirms

Results will be published in the July 2011 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"Few studies have used a broad population-based approach to examine associations between a parental history of AUD and risk of an AUD in offspring," said Erik Lykke Mortensen, associate professor in medical psychology at the University of Copenhagen and corresponding author for the study. "Longitudinal population studies are both expensive and take a long time to complete. In some countries it may also be a problem to follow several generations through decades. But in Denmark we have personal identification numbers and national health registries."

Mortensen and his colleagues gathered data on 7,177 individuals (3,627 men, 3,550 women) born in Copenhagen between October 1959 and December 1961: information on AUDs was gathered from three Danish health registers, and information on other psychiatric disorders (OPDs) was gathered from the Danish Psychiatric Central Register. Offspring registration with an AUD was analyzed in relation to parental registration with an AUD and/or OPD. The gender of the offspring and parental social status were also noted.

Results showed that parental AUDs were associated with an increased risk of AUDs among the offspring, independent of other significant predictors such as gender, parental social status, and parental psychiatric hospitalization with other diagnoses.

"Furthermore, this association appeared to be stronger among female than male offspring, which suggests that inherited factors related to AUDs are at least as important among daughters as among sons," said Mortensen. "This finding is important because some early studies suggested that a genetic load played a stronger role in males than in females."

One of the important aspects of this study, added Mortensen, is that contrary to a number of previous adoption and twin studies -- often based on relatively small and selected samples -- these findings represent risk estimates from a population-based study.

"The key message for the general public is that there is an increased risk associated with parental alcoholism," said Mortensen, "but obviously many other factors determine whether an individual develops an AUD."