Psychometric support for contemporaneous and retrospective youth and parent reports of adolescent marijuana use frequency in an adolescent outpatient treatment population.

Little is known about the reliability and validity of self-and collateral reports of adolescent drug use frequency within adolescent treatment samples. Therefore, in the present study drug counselors systematically obtained contemporaneous reports of adolescent marijuana use frequency from 31 conduct-disordered and drug abusing youth, and separately, their parents, during each outpatient treatment session for 6 months. A urine drug screen was also scheduled to occur during each treatment session. At the conclusion of treatment, a blind assessor obtained retrospective reports of the youths' frequency of marijuana use during each of the six months of treatment from both the adolescents and their parents using the Timeline Follow-Back (TLFB) procedure. With only one exception (i.e., parents reported that their children had used marijuana more often in the first month of treatment according to the retrospective TLFB method, as compared with the contemporaneous method), contemporaneous and retrospective reporting methods yielded similar information throughout each of the 6 months of treatment for both youth and their parents. A significant positive relationship between urinalysis testing and youth reports of their drug use was found for each of the 6 months of treatment. Similar relationships with urinalysis testing were generally found to exist in both parent report methods (i.e., contemporaneous, retrospective) across the 6 months of treatment. The results suggest adolescents and their parents provide consistent reports of marijuana use frequency throughout treatment, and that these reports are corroborated utilizing standardized retrospective reporting methods and urinalysis testing. Future directions are discussed in light of these findings.