All three participating studies (COGA, COGEND, and FSCD) used the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA; Bucholz et al., 1994). Childhood abuse (CA) was dichotomously coded into participants reporting no physical or sexual abuse (n = 549) or at least one instance of physical or sexual abuse, defined as physical injury by or forced sexual contact with a relative or someone other than a family member before the age of 16 (n = 310). Physical abuse was included due to the smaller sample and limited sexual abuse of the sample. Of our final participants, 65.7% reported having ever used cannabis. As in CATS, dependence symptoms were defined as the number of lifetime DSM-IV dependence symptoms reported (Table 3; M = 1.22, SD = 2.00); due to the relatively small sample size, individuals who had never used cannabis were included in these analyses and coded as “0” dependence symptoms. Distributions of cannabis dependence symptoms across genotype and CA groups are provided in the Supplement (Table S3).
