Long stays are often thought to result from outdated methods of treatment, so that modernization should bring them to an end. The purpose of this work is to find out whether old and new long stay patients are to be found in French psychiatric institutions, as they have been in several other countries, and if so, describe some characters of the patients, in order to give a better understanding of the situation. As early as 1972, Wing and Hailey were able to study old and new long stay patients in the Camberwell register. In 1987, Kastrup published the results from the Danish national cohort; among other conclusions, she was able to show that some patients experienced a long stay when admitted for the first time, while others only did so later during the course of their treatment. In 1994, Lelliott and Wing, published the results of a British national audit of new long stay patients; they reiterated that the closing of psychiatric hospitals should go along with the opening of specialised long stay and rehabilitation facilities. Trieman, Leff, and several other researchers members of the Team for the Assessment of Psychiatric Services (TAPS) published many articles describing the follow-up of patients staying in two large hospitals undergoing closure near London. One of these papers concludes that "difficult to place patients will not disappear with the closure of the psychiatric hospitals..., they continue to arise from the population of patients recently diagnosed". At the end of 1998, a national survey was organised according to the recommendations of the United Nations and of the World Health Organisation by the French National Institute of Statistics and of Economic Studies (INSEE). Its general purpose was to describe disabilities in the French population on a census day. To that end, information was also recorded about schooling, employment, income, lodging, family relations, etc. Persons who were notable to answer by themselves were included; if not, many severe cases would have been excluded. A follow-up survey of the same persons took place 2 years later. Interviews were carried out by trained interviewers of the INSEE. Medical information was recorded from what the patients themselves knew or could say. The survey included a random sample of inpatients in psychiatric institutions. We study here specialised hospitals: this does not include psychiatric wards in general hospitals, nor private hospitals. Compared to what had been planned, the proportion of successful interviews in psychiatric institutions was 75%. The 1180 persons who answered the questionnaire bring information about the estimated 33,600 who were in these psychiatric institutions at the end of 1998. Information about where the persons were by 2000 could be collected about almost all of them. This paper deals with length of stay, sex, age, marital status, age at admission, place of residence before entering hospital and outcome at the end of year 2000 All data relating to age and duration were studied by splitting groups into quartiles. No multivariate analysis was made, since information about diagnosis and disabilities was not included. Among the 33,600 in-patients, six out of ten were men. A quarter were under 32 years of age, half under 43. Two thirds of the patients were bachelors. One patient out of ten had been in hospital for 15 days, and one out of five for 30 days; half had been in hospital for 7 months; the duration of stay was over 1 year for 41%, over 5 years for 23% and over 18 years for 10%. Before being admitted, more than four patients out of ten (44%) lived in an independent home, one out of six (16%) lived with his-her parents more than one out of four (28%) lived in another institution. When they were admitted, one patient out of four was 26 years of age or younger, and one out of two was two was 38 or younger. Men, bachelors, and patients between 43 and 54 years of age had longer lengths of stay than the average. Patients admitted before the age of 26, and in particular those admitted before they were 18, had the longest length of stay. Patients who lived in an independent home were in hospital for a much shorter time than those who lived with parents before being admitted. Patients coming from institutions for the elderly had lengths of stay very much similiar to those patients who lived in an independent home before being admitted. In these cases, hospital was for the most part normal place for treatment. Patients coming from institutions for disabled persons had very long lengths of stay. Among the 33,600 patients, one out of ten was living in an institution for disabled persons before being admitted and had been in hospital more than a year. The follow-up showed that among those who had been in hospital for less 16 days by the end of 1998, 6% were in the same institution two years later. For those who had been there for less 41 days, the proportion was 11%. On the other hand, an those who had been in hospital for more than 4 years by the end of 1998, 7% were in an independent home 2 years later. Before being admitted, 44% of the patients lived in an independent home, but only 34% were in such a setting by the end of year 2000. An important minority (43%) was in the same hospital by the end of 2000. The proportion of patients who were in the same hospital 2 years later was higher at younger ages, among those who lived previously with parents, or who came from institutions for disabled persons, or who were admitted before the age of 26. had been in hospital for over 4 years by the end of 1998 and who were in the same hospital 2 years later were admitted at younger ages (eight out of ten were admitted before the age of 38); a large minority (31%) lived previously in an institution for disabled persons. The global death rate in two years was 7%, with a standardised mortality ratio of 4. Patients who lived in an institution for adult disabled persons before being admitted in hospital had a standardised mortality ratio of 10. These data very much suggest that many patients in French psychiatric institutions suffer from severe problems that prevent them from living in an independent home or even in an institution for disabled persons. A large number of persons seem to have been admitted in hospital at a time when it was not anymore possible for them to go on living in the previous setting: after treatment, they were not able to go back to where they came from. Indeed, a survey organised on a census day will over represent the longer stays and the more severe patients. On the other hand, outpatient treatment is very much organised in French public sectorised services, so that it is mainly those who suffer from severe problems who will go to hospital. The data also show that old long stay patients are slowly being replaced by new ones. The splitting of all groups into quartiles shows that there is no clear cut between short and long stay patients. The usual definition (over a year) is simple and convenient, yet is not a definite boundary between 2 separate groups. The analysis of allthese data can be organisedalong2 lines: one approach describes the patients, a complementary one provides information about services. The first approach will underscore the many social abilities that are necessary in order to live in an independent home. Younger age at outset will often be related with more serious mental illness. Considering that marriage usually happens later in our modern society, social withdrawal associated with mental illness will less often be balanced by the family and by relatives, so that patients may tend to stay longer with their parents. On the other hand, the fact that some patients who have been in hospital for a long or a very long time may nevertheless be found in an independent home two years later shows that long stay patients are not neglected. The second approach, about services, draws on the history of French psychiatric institutions: in the past, specialised wards for children were very poorly staffed and received patients with most severe problems. Some of these patients have now become adults and live in the hospital where they were admitted as children. Another question is about how services should be organised so that patients will be able to stay out of hospital despite their severe problems in daily life. A third question is about institutions for disabled persons, who are supposed to provide shelter for patients with disabilities, yet fail to do so for a number of them, so that these persons are admitted to a psychiatric hospital, then cannot leave it. This first French national random survey in psychiatric institutions, with two-year follow up, shows that old and new long stay patients are found in French psychiatric institutions. The results provide information about the patients; they can also help planners in order to improve appropriate services.