Such a severity continuum, which often correlates with important variables in alcohol research such as alcohol treatment outcome (McKay & Weiss, 2001; Walton et al., 2003), can be conceptualized in various ways. The DSM-IV (APA, 1994) classifies two types of alcohol-use disorders, abuse and dependence. Abuse requires fewer symptoms to diagnose than dependence and is excluded for individuals who meet the criteria for dependence. Thus, an important difference between the two diagnoses involves the number of problems, as opposed to the types of problems manifested. Although some of the criteria for alcohol dependence include physiological markers of alcohol effects (e.g., tolerance, withdrawal), it is not necessary for these markers to occur to meet the diagnostic criteria. Factor analytic research does indicate that features of withdrawal have high symptom loadings on the dependence factor (Langenbucher et al., 2000). Also, requiring withdrawal symptoms for the diagnosis of alcohol dependence increases the reliability of the diagnosis, results in higher predictive validity, and is more consistent with theoretical models of the relationship between abuse and dependence (Langenbucher, et al.). It is thus possible that
