Nationwide study on antipsychotic polypharmacy among forensic psychiatric patients.

This nationwide retrospective cross-sectional study examines the prevalence of antipsychotic polypharmacy (APP) and demographic, forensic, and clinical factors associated with its practice among Greenlandic forensic psychiatric patients. We collected data from electronic patient files, court documents, and forensic psychiatric assessments. We defined APP as two or more concurrent prescriptions of antipsychotic medication. The study population of 74 patients had a mean age of 41.4 years, and 61 were men. All included patients had either schizophrenia or another ICD-10 F2-diagnosis. We used unpaired t-tests and Chi2 or Fisher's exact test. The prevalence of APP was 35% (n = 26), and there was a significant association between APP and a prescription of clozapine (Chi2, p = 0.010), olanzapine (Fisher's test, p = 0.003), and aripiprazole (Fisher's test, p = 0.013). Furthermore, we found a significant association between APP and prescription of a first-generation antipsychotic (FGA) (Chi2, p = 0.011). Despite recommendations in guidelines, the use of APP is common practice. The majority of forensic psychiatric patients suffer from severe psychiatric disorders, often with other comorbidities, including substance use disorder. The severity and complexity in mental health render forensic psychiatric patients at high risk of APP treatment. Further knowledge on APP use is crucial to secure and further improve the psychopharmacological treatment for this group of patients.