The recanting of earlier reported drug use by young adults.

One approach to determining the validity of self-reported drug use measures is to examine the extent of logically inconsistent responses over time. Because lifetime use logically should never decline, the rate of subsequent recanting of earlier reported lifetime use provides relevant evidence on validity. In this chapter, recanting rates are examined in nationally representative samples of high school seniors (18-year-olds) surveyed in the Monitoring the Future study as they are followed up on seven occasions through age 32. For the illegal drugs examined (marijuana, cocaine, and lysergic acid diethylamide (LSD)), recanting rates prove to be quite modest, but for the psychotherapeutic drugs, they were more substantial, possibly because of their greater definitional ambiguity. In general, there were no large individual differences in recanting rates as a function of sex, household composition, community size, or education level. Consistent with previous work, minorities (particularly African Americans) had somewhat higher rates of recanting on the illegal drugs. So did respondents in certain occupations, namely, the military and police/firefighting. In general, however, the evidence is quite good for validity of self-reported (by mail) lifetime use of the illegal drugs in young adulthood.