Background: Temperance boards were established in Sweden to register and follow up individuals who were seen in legal or medical settings with problems of alcohol abuse. These records, available in a large epidemiologic twin population, have provided an objective and validated measure of alcohol abuse.
Methods: We examined Swedish temperance board registrations from 1929 to 1974 (n = 2516 individual twins) in all male-male Swedish twin pairs of known zygosity from the population-based Swedish Twin Registry; these twin pairs were born from 1902 to 1949 (n = 8935 pairs).
Results: The lifetime prevalence and probandwise concordance rates for temperance board registrations were 13.2% and 47.9%, respectively, in monozygotic twins and 14.6% and 32.8%, respectively, in dizygotic twins. Model fitting suggested that genetic and familial-environmental risk factors accounted for 54% (95% confidence interval [CI], 47%-61%) and 14% (95% CI, 8%-19%) of the liability to temperance board registration, respectively; these estimates were stable across birth cohorts. High genetic liability was reflected by large numbers of temperance board registrations and registrations for criminal alcohol use. Elevated familial-environmental liability was indicated by an early age at first registration.
Conclusions: Genetic factors are of major etiologic importance for alcohol abuse in men, while familial environmental factors play a significant but less important role. The etiologic importance of these factors has remained constant in Sweden for men who were born in the first half of the 20th century.