We used two different approaches to test the extent to which the childhood maltreatment–AAD association is explained by familial influences. First, a co-twin control design was employed to estimate the maltreatment–AAD association after adjusting for unmeasured family effects. The odds ratio (OR) for AAD was calculated in three groups: MZ twin pairs discordant for childhood maltreatment (87 pairs); DZ twin pairs discordant for childhood maltreatment (74 pairs); and risk for AAD based on childhood maltreatment status in the sample overall (n=3527).
