mailings, drivers license records, as well as the random selection among participants in medical or dental clinics (Bucholz et al., 1994; Schuckit et al., 1996). All original probands, available first and second degree relatives including these offspring, and members of control families were interviewed by personnel trained on the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) instrument (Bucholz et al., 1994; Hesselbrock et al., 1999). The SSAGA has good to excellent reliability for alcohol and drug use disorders, and good validity regarding these diagnoses when compared to an additional structured research instrument. The 55 offspring included here were all followed-up five years later with a SSAGA interview focusing on the interval period.
