The aim of this paper is to provide an overview of epidemiological, clinical and psychosocial characteristics of patients needing long-term treatment. The data concerned the following aspects: prevalence and incidence from the five best-established Italian psychiatric case registers; needs for care; psychosocial and clinical outcome as assessed by means of follow-up studies; social disability and relatives' perceived burden. The one-year prevalence rate of "long-term users" is consistent in Northern Italy, higher in Middle Italy and lower in Southern Italy. The incidence rate was found to be around 4 per 100,000. Even in a community oriented mental health service, users' needs for care are only partially met. A good psychosocial outcome was found associated with the use of social and/or vocational skills training, while the average number of days per year of hospitalization in a psychiatric department was found associated with poor outcome. A moderate degree of social disability was found among patients needing long-term treatment. The resulting family burden presented to a marked or very marked degree in more than 50% of the relatives.