[Day Hospital: history and conceptualization]

The appearance of Day Hospitals operated as a model to inspire the different ways of partial time psychiatric care (night hospitals, weekend hospitals, long hour activities in hospitalization services or general hospitals, etc.) and came to complement or replace complete hospitalization in classic psychiatric hospitals. This article presents the history and origins of Day Hospitals and their initial propagation in different countries, and especially in Argentina. Social and political conditions that set their emergence as a therapeutic resource in psychiatry, their models of functioning and variants of application according to the diagnoses of patients admitted, age groups, etc., the theories put into play to report their effects, several studies and technical results, and ideological views related to mental disorders and their treatment in the society are also being studied.