Demographic variables included gender (male, with female as referent), age category (12–17, 18–25, with 26 and older as referent) and race/ethnicity (non-Hispanic Black, Native American/Alaskan Native, Hawaiian/PI, Asian, non-Hispanic more than one race, Hispanic, with non-Hispanic White as referent). We retained the age categories conventionally used in the NSDUH reports in view of the study focus on adolescents and younger adults. While the boundary between ages 25 and 26 are somewhat arbitrary, age-specific symptom distributions in a previous NSDUH survey (Harford et al., 2005) provide some justification for these categories.
