Assessing cannabis use in adolescents and young adults: What do urine screen and parental report tell you?

Objectives: Our analysis compares three approaches to detect the most common drug abused in early adulthood, cannabis: (1) report on direct structured interview; (2) indirect parental report; and (3) urine toxicology screen. Methods: We examined data on 207 subjects (36% also met criteria for alcohol abuse; 9% for alcohol dependence) derived from two prospective arid ongoing family studies of boys and girls with or without attention-deficit/hyperactivity disorder (ADHD). Assessments relied on the Schedule for Affective Disorders and Schizophrenia (K-SADS-E; under 18 years of age) and on the Structured Clinical Interview for DSM-IV (SCID-IV; over 18 years of age). Urine samples were analyzed with Auccusign DOA5 (on-site screening assay). Results: Ninety-seven percent (97%) of individuals, who reported no use of cannabis within the past month, had a negative urine screening and 79% of individuals, who endorsed cannabis abuse/dependence, had a positive urine screening. The sensitivity of the direct structured interview report was 91%, the specificity 87%, the positive predicting value 67%, and the negative predictive value 97%. Indirect parental reports were found to be less informative on cannabis use than direct report. Conclusion: Direct report of cannabis use, abuse, or dependence during the structured interview is both sensitive and specific when compared to urine toxicology screens and indirect parental reports.