Data on parental history of externalizing related disorders came from parents’ SSAGA interviews (Bucholz et al., 1994; Hesselbrock et al., 1999) from earlier phases of the COGA study. Among the EA analytic sample, parental SSAGA data were available for 666 (93%) of the mothers (age at last assessment, M = 33.72 years, SD = 7.05) and 511 (71%) of the fathers (age at last assessment, M = 36.33 years, SD = 7.39). Among the AA analytic sample, parental SSAGA data were available for 355 (91%) of the mothers (age at last assessment, M = 32.00 years, SD = 6.76) and 184 (47%) of the fathers (age at last assessment, M = 33.72 years, SD = 7.90).
