Personality disorders and schizophrenia spectrum disorders in the Italian forensic psychiatric population: clinical features, pattern of violence and treatment.

Starting in 2015, the Residencies for Execution of Security Measures (REMS) became the place of treatment and care for dangerous offenders who were acquitted due to a mental disorder in Italy. Schizophrenia spectrum disorders (SSD) and personality disorders (PD) are the most common psychiatric disorders among REMS patients. This study aimed to identify and describe potential clinical, therapeutic, and criminal-related differences in REMS patients with SSD and PD. A sample of 528 REMS patients extracted from a previous observational retrospective study underwent secondary analysis. The group of PD patients (n = 150) comprised more females (p < 0.001) and had a higher frequency of substance abuse (p < 0.001) than the SSD group (n = 378). The SSD group was more frequently admitted to the REMS due to homicide/attempted homicide (p < 0.001). Among SSD patients, we found a higher recognition of criminal irresponsibility (p < 0.001). Patients with PD were more likely to engage in violent behavior in the REMS than their SSD counterparts (p < 0.001). Patients with SSD were more likely to receive antipsychotic polypharmacy (p < 0.05) and a higher dose of antipsychotics (p < 0.001). These initial results provide empirical evidence to support the need for personalized forensic treatment paths.