We found little evidence for bias from incomplete twin pairs. Prevalence of childhood maltreatment and AAD did not differ in participants from complete versus incomplete pairs (all p>0.05). The childhood maltreatment–AAD association differed minimally by completion status (i.e. among all individuals, tetrachoric correlation ρ=0.21, among individuals from complete pairs only, ρ=0.18). Individuals with and without parental psychopathological data did not differ on prevalence of childhood maltreatment or AAD, or in the maltreatment–AAD correlations.
