these data suggest that the abuse-dependence distinction currently outlined in DSM-IV might be reconsidered for DSM-V. We provide evidence that a diagnostic system that considers all the abuse and dependence items together will more accurately scale adolescents on AUD severity. The proposed alternative diagnostic algorithm results in more accurate prediction of severity of AUDs across diagnostic category (based on explained variance), and lower variability in AUD severity within diagnostic categories (bottom panels Figure 4) compared with the current DSM-IV diagnostic algorithm. The alternative algorithm does not change the severity of abuse and dependence diagnoses on average (Table 2). In addition to the benefit of more precise measurement of AUD severity, the alternative algorithm is advantageous because it eliminates diagnostic orphans, a frequently cited problem with the current abuse-dependence distinction 8, 9, 36, 37. Adolescent diagnostic orphans are troubling because they have high rates of other drug use and clinically significant problems commensurate with their counterparts who qualify for diagnoses 38. Additionally, defining abuse and dependence as categorical classifications derived from a continuous measurement scale could be beneficial for studies that require reliable and accurate characterization of the severity of alcohol use problems. Some examples include genetic studies where power is
