Limitations of scalogram analysis as a method for investigating drug use behavior.

Scalogram analysis, a procedure developed for constructing attitude scales, has been recently applied to support certain conclusions about the typical development of drug use patterns. An examination of results from these applications revealed at least three potential limitations: (1) presumed drug usage patterns may not generalize to many drug users, especially adult users; (2) presumed patterns may not be supported if several commonly used psychoactive substances are included; and (3) measures of unidimensionality may not be sufficient for confirming actual unidimensionality of highly skewed drug use patterns. Therefore, the present study was designed to investigate further these potential limitations and to determine their bearing upon previous theoretical conclusions. Results confirmed the existence of all three limitations. In other words, typical applications of scalogram analysis based upon adolescent illicit drug use data have questionable external and internal validity. Therefore, previous conclusions based upon such applications should be re-evaluated and future research should employ alternative analytical procedures.