Opening the black box of hospitalizations in French high-secure psychiatric forensic units

Basic epidemiological data are rare concerning the activity of specialized forensic psychiatric facilities in France. Here, we investigated the activity of the ten (640 beds) French "units for difficult patients" (unités pour malades difficiles [UMDs]).

We used the Programme de médicalisation des systèmes d'information (PMSI) database to describe the characteristics and evolution of psychiatric hospitalisations in UMDs between 2012 and 2021, as well as the age, sex, and principal diagnoses of the patients hospitalized in these facilities.

Between 2012 and 2021, 4857 patients were hospitalized in UMDs (6082 stays). Among them, 897 (18.5%) had more than one stay. The number of admissions ranged from a minimum of 434 to a maximum of 632 per year. The number of discharges ranged from a minimum of 473 to a maximum of 609 per year. The mean length of stay was 13.5 (SD: 22.64) months with a median of 7.3 months (IQR: 4.0-14.4). Among the 6082 stays, 5721 (94.1%) involved male patients. The median age was 33 (IQR: 26-41) years. The most frequent principal psychiatric diagnoses were psychotic disorders and personality disorders.

The number of individuals hospitalized in specialized forensic psychiatric facilities has been stable for 10 years in France and remains lower than in most European countries.