Through record-linkage in the national patient register for mental hospitals one can examine how many patients are rehospitalized within one year. The results of this examination suggest that the recidivism of mental patients is one of the foremost problems confronting hospital psychiatry today. It was found that from 1970 up to 1980 the increase of 'sisyfus'-patients was greater thari of patients who only once were hospitalized in the same year.
The admissions in 1980 were examined more carefully. Data of the 'sisyfus'- patients on first admission were compared with data of mental patients who only once were admitted, after standardization on age and sex. Comparing both groups revealed significant differences in diagnosis, marital status, residence before admission and lenght of stay in hospital. Crosstabulations of these variables suggest that within the readmission group some high risk patients can be found.