Differences also exist in the methods used for ascertaining FH. Most often, information about family members is gathered either by directly interviewing each family member (direct FH method) or by having assessed family members report the alcohol use problems of unassessed family members (indirect FH method). Importantly, variations in ascertainment methods also affect the criteria used for determining affectedness of family members. For example, in the direct FH method, family members are directly interviewed using instruments such as the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) (Bucholz et al., 1994), in which the diagnostic criteria, as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM; e.g., DSM-IV/DSM-5) are already incorporated into the instrument. Whereas, in the indirect FH method, instruments such as the Family History Assessment Module (FHAM) (Rice et al., 1995) are used where a relative’s affectedness is decided based on predetermined criteria—a family member has to be named by three or more family members to be considered “affected”.
