A reassessment of participants in a genome‐wide association study (GWAS) (Heath et al. 2011) of alcohol dependence and heaviness of drinking termed the OZ‐ALC GWAS, focused on childhood and adult environmental stressors. The GWAS sample was ascertained through index cases identified via surveys of two large general population Australian twin cohorts (cohort 1, born 1890–1964 [but mostly 1940–1964], and cohort 2 born 1964–1971), (Heath et al. 1997; Knopik et al. 2006) the spouses/partners of cohort 1 twins, (Grant et al. 2007) and an Australian population‐representative sample that ascertained families containing five or more full siblings. Recruitment of families in which a member reported a history of childhood trauma at prior interview was prioritized. Excluding CT Study participants and those with missing Christchurch Trauma Assessment data, a sample of 747 women and 791 men (mean age 53.0 years [SD 8.2]) were retained for the current analyses. Verbal consent was obtained preinterview as per the protocol approved by the QIMR Ethics Committee and the WUSM HRPO.
