For ANYDEP, individuals were considered affected if they met DSM-IV lifetime dependence criteria for any of the 4 substances, and unaffected if they did not meet DSM-IV dependence criteria for all 4 drugs. Individuals younger than 23 years old at their most recent interview who did not meet criteria for dependence on any of the 4 drugs were recoded to missing/unknown (n=408) because they had not passed through the primary age of risk. Selection of this age cutoff was based on the median age of onset of alcohol, cannabis, cocaine and opioid/heroin dependence in the White subsample of the U.S. population based National Epidemiologic Survey of Alcohol and Related Conditions (NESARC) (Grant et al., 2004; Hingson et al., 2006). The median ages ranged from 18-22 years, supporting a cutoff of 23 years. In addition, those individuals with insufficient SSAGA to determine whether they were or were not dependent were also coded as unknown (n=144).
