In the first decades of the twentieth century, German-language papers were published which included the term “soziale Psychiatrie” in their titles. At the same time modern concepts of extramural psychiatric care were being developed. Yet, the meaning of “sozial” (“social” in English) varied widely. This was partly due to its ambiguity. “Social” can be used in the sense of small communities or the wider public; it refers to interpersonal relationships, or to relationships between individuals and social groups or other communities. According to this latter meaning, “social” can emphasize the interests of social groups rather than those of the individual. This is how the term was used at the end of the 1920s and during the National Socialist era. On the other hand, “social” may indicate a friendly and humane intention, a philanthropic approach. It was in this sense that the term was widely used in the 1970s when philanthropic psychiatrists and others called for psychiatric reform and the closure or downsizing of asylums for the mentally ill. Moreover, in association with psychiatry, it can mean both the social dimension of mental illness (including the aetiology) that is assumed to lie in human relationships and in social circumstances, and the social and economic effects of mental illness. In parallel with these shifting meanings of the term “social”, the established models of twentieth-century ambulant psychiatric care also showed a variety of structural characteristics.