Abstract
Item response theory (IRT) has advantages over classical test theory in evaluating diagnostic criteria. In this study, the authors used IRT to characterize the psychometric properties of
Diagnostic and Statistical Manual of Mental Disorders
, 4th edition (
DSM-IV
;
American Psychiatric Association, 1994
) alcohol and cannabis use disorder symptoms among 472 clinical adolescents. For both substances,
DSM-IV
symptoms fit a model specifying a unidimensional latent trait of problem severity. Threshold (severity) parameters did not distinguish abuse and dependence symptoms. Abuse symptoms of legal problems and hazardous use, and dependence symptoms of tolerance, unsuccessful attempts to quit, and physical-psychological problems, showed relatively poor discrimination of problem severity. There were gender differences in thresholds for hazardous use, legal problems, and physical-psychological problems. The results illustrate limitations of
DSM-IV
criteria for alcohol and cannabis use disorders when applied to adolescents. The development process for the fifth edition (
DSM-V
) should be informed by statistical models such as those used in this study.