The term "co-dependency" has become somewhat established within the vernacular of the addiction field and is being used increasingly within the popular psychology and self-help literature. A review of this literature reveals that there is general agreement as to the core characteristics of co-dependency but virtually no agreement as to a workable definition. Remarkably little research has been published to examine any of the assumptions within the model, so that most of the ideas presented in the literature rest on clinical observation and/or personal experience. The concept has been widely criticized from a number of theoretical perspectives. Of particular note are the feminist objections to the model. In addition, a number of the central concepts within the co-dependency model are at odds with some of the research into family coping. Further research is urgently needed in this area. Despite many conceptual problems the development of this model has had an undoubted positive influence on family treatment and support benefiting many people within the self-help arena.