In the period of 1970-1975 the amount of informal admissions to mental hospitals increased considerably. In 1977 the ratio of informal to formal admissions tumed out to be 85 percent to 15 percent. Concerning the number of formal admissions (committals to custody and judicial admissions) there was a sharp increase of the committals to custody, whereas the number of judicial admissions decreased. Not all informal admissions proved to remain informal during the patient's stay in the hospital. In a cohort of 2772 patients, admitted in 1973, twelve different patterns of legal situations were found. The period between the various legal situations appeared to vary, f.i. the period of an informal admission turned out to be shorter if followed by a committal custody than by a judicial state.