Analyses of the prevalence and incidence of withdrawal symptoms in the general population can provide an estimate of the frequency of alcohol dependence in the population. Similar analyses in people who are being treated for alcoholism or alcohol-related problems can identify the need for and specific types of treatment required for these populations. Three national surveys found that the prevalence of withdrawal symptoms was relatively low in the general population and has remained stable over the past 15 years. The likelihood of experiencing withdrawal symptoms increased with increasing alcohol consumption. No differences in the prevalence of withdrawal symptoms existed among ethnic groups in the general population. In a sample of patients undergoing alcoholism treatment, the prevalence of withdrawal symptoms generally was high, with lower rates among blacks than among whites and Hispanics. The prevalence of withdrawal symptoms in people undergoing treatment after being convicted of driving under the influence fell between that of the general population and that of the treatment sample.