The use of intoxicants is indexed in American history adopting a social perspective of the role of alcoholism in traditional American society. Appealing to societal patterns, the elaboration of substance abuse as a disease is explored with a diagnostic focus on intervention as it relates to pathogenesis. Using clinical vignettes, the ego is proposed as the focus of pathology in the addiction process, featuring a regression to the defenses of projection and denial. Following the model proposed in Zinberg's seminal paper on addiction and ego function, various deficits are annotated that typify such regression. The ultimate clinical picture is one of ego atrophy, where basic interests and object relations are usurped by the all-consuming preoccupation with the substance of abuse.