We examined several demographic variables that could affect the maltreatment–AAD association, including participant age and parental birth year, age at twins' birth, education, and income. In exploratory analyses, we examined several variables that could account for the childhood maltreatment–AAD association, including primary major depression, parent–child relationships, and parental psychopathology. Primary major depression was defined as a first episode of major depression occurring prior to the age of first alcohol problems (or at any age for individuals without alcohol problems). Lifetime major depression diagnosis was made using DSM-IV criteria based on a structured diagnostic interview assessment, adapted from the SCID and administered by clinically trained interviewers.
