Chronic social disablement is caused by three types of factor: impairment, e.g. slowness in schizophrenia; social disadvantage, e.g. lack of opportunity to develop social or vocational skills; and an underconfidence or unduly low self-esteem which is reactive to impairment and disadvantage. The last of these factors is particularly evident in 'institutionalism', a condition in which the individual comes to acquire a contentment with institutional life and wishes to lead no other. Many long-stay patients in large mental hospitals used to be 'well-institutionalized' but it became recognized that retraining and rehabilitation could lead to successful resettlement outside hospital. For a time these striking successes suggested to some theorists that abolishing the hospitals would abolish disablement as well but it is now quite clear that this is not the case. Chronic impairments still occur and create a continuing need for sheltered environments. The frequency and type of problems still arising are discussed in the light of recent surveys in England. One small group requires highly-staffed accommodation, others need less supervised day and residential settings; all need long-term care. It is emphasized that some people living at home with relatives also have chronic mental disabilities as have a high proportion of the destitute. Such problems are less frequent than formerly but they still require detailed medical and social attention.