The DISC (Fisher et al., 1993; Piacentini et al., 1993; Schwab-Stone et al., 1993; Shaffer et al., 1993) is a highly structured psychiatric interview for children and adolescents, specifically designed for use by lay interviewers in epidemiological studies. The DISC questions are organized around diagnostic categories. The DISC provides both diagnostic scoring for DSM diagnoses, as well as symptom scales. Extensive evaluation of the psychometric properties of the DISC has been conducted, demonstrating its interrater reliability, test–retest reliability, criterion validity, and sensitivity (Fisher et al., 1993; Piacentini et al., 1993; Schwab-Stone et al., 1993; Shaffer et al., 1993). At Waves 3 and 4 of the study, the substance use module of the DISC was administered. The total count of CAD symptoms in the past year was utilized as the primary outcome measure of interest.
