This chapter outlines the historical background of alcohol problems, current classificatory systems for diagnosis, psychological and physical related disorders, and the epidemiology of alcohol disorders. A variety of research methodologies have been adopted to examine the relative contribution of genetic and environmental factors to alcohol dependence. Explanatory models for age and sex differences in adolescent drug use can be derived from a variety of theories, including social learning theory and social control theory. The general protocol is adapted from that developed for nicotine dependence and is a useful way to formulate the assessment process, because it translates into specific management plans. Psychological treatments are pivotal to treatment effectiveness, even when pharmacological treatments are administered. The relationships between alcoholism and other psychiatric disorders are some times complex, and it is not always easy to achieve abstinence from alcohol to make an adequate assessment of the nature of the relationship.