ABSTRACT

This PhD dissertation was carried out at the H:S Institute of Preventive Medicine, the National Institute of Public Health, University of Southern Denmark, and at Department of Psychiatry, Columbia University, USA. The purpose was to analyze, epidemiologically, aspects of alcohol use disorders (AUD) in a Danish population.

The dissertation is based on the Copenhagen City Heart Study, which is an ongoing series of studies conducted in the Danish population from 1976 and onwards. All participants were followed by use of the unique personal identification number with linkage to registers: The Danish Hospital Discharge Register, the Danish Psychiatric Central Register, the WINALCO-database, and the Danish Causes of Death Register.

In the first study, we found that amount and frequency of alcohol intake were significantly associated with an increased risk of AUD. With the reference group being non-drinkers, the thresholds of significance were very different for men and women, since women significantly increased their risk by drinking 1-7 drinks per week, whereas the risk for men showed no significant increase before weekly intakes of alcohol of more than 21 drinks per week.

In the second study, we found that individuals who drink wine as part of their alcohol intake have a lower risk of AUD compared to individuals who do not include wine, irrespective of the total amount of alcohol consumed. We concluded that the findings were most likely to have appeared due to confounding factors that were not assessable in the study, rather than to specific ingredients in different types of alcohol.

In third study, we found that if the reference group was non-drinkers, women were at increased risk of psychiatric disorders only if they drank more than 14 drinks per week. For men there was no increased risk of any psychiatric disorder with high intakes of alcohol. Conversely, drinking alcohol every week seemed to have a protective effect towards psychiatric disorders in men.

In the fourth study, we concluded that AUD is frequently co-morbid with other psychiatric disorders. First-time AUD registration was most likely to precede first-time registration of psychiatric disorders, such as mood disorders, psychotic disorders, anxiety disorders, personality disorders, and drug abuse. And the risk of developing a psychiatric disorder in individuals with AUD seemed to be greater than the risk of developing AUD in individuals with other psychiatric disorders.

In the fifth study, we found that individuals with AUD are at increased risk of committing suicide, and that registered co-morbid psychiatric disorders were neither sufficient nor necessary causes in this association. The findings may however be a result of the fact that analyses are based on register information.