We asked participants whether they were currently cohabiting with, or had ever cohabited with, a first-degree relative (sibling or parent) who had an “alcohol problem”. Responses to this question were coded as 0 if the participant had never cohabited with such an individual; 1 if the participant had cohabited with a single first-degree relative with an alcohol-use problem; and 2 if the participant had cohabited with more than one first-degree relative with an alcohol-use problem. This approach was adapted from the family history drinking questionnaire described by Mann et al. (1985).
