In 1980 the psychiatric clinic of the University of Hamburg took charge of a catchment area within the city of Hamburg. From this year on the clinic decided to provide half of its in-patient and day clinic capacity (that is 71 beds and 10 day clinic places) for a population of 139,000 living in this region. The effects of this decision are discussed on three levels: - changes in the patient population - opinions and attitudes of the clinic personnel - implications for the organizational structure Results: The proportion of in-patients from the catchment area increased from 20% to 45% due to the clinic taking charge of this region. This increase did not much change the characteristics of the total in-patient population admitted to the clinic, except for a shift towards more older patients and more patients with a diagnosis of dementia or organic psychosis. Around two thirds of the clinic personnel held a predominantly positive view of the clinic's decision to establish a catchment area. Contrary to some hopes the internal structure of the clinic did not change much in response to its newly acquired responsibility for the catchment area. Nevertheless a period of one year seems too short for such changes to occur.
