clinics from 2001 to 2010 (excluding Primary Health Care); the Primary Health Care Register, containing outpatient diagnoses from 2001–2007 for around 1 million patients from Stockholm and southern Sweden; the Crime Register that included national complete data on all convictions in lower court from 1973–2011; and the Swedish Suspicion Register that included national data on individuals strongly suspected of crime from 1998–2011. From the twin register we identified twin pairs with known zygosity, and from the Multi Generation Register we derived full and half siblings born within five years from each other. We included same-sex pairs where both individuals were born between 1940 and 1965, alive and living in Sweden at age 35. As detailed elsewhere (34), zygosity in the same-sex pairs from the twin registry was assigned using standard self-report items from mailed questionnaires. This is an indirect screening for level of cooperation because at least one of the pair had to return a questionnaire to the twin registry and cooperation was lower in subjects with AUD thus the prevalence is lower in this group compared to twins pairs not returning the questionnaires.
