Polypharmacy in antipsychotic pharmacological treatment among patients with dual diagnosis in Denmark

Introduction: Antipsychotic polypharmacy is prevalent, however literature on antipsychotic polypharmacy during treatment among patients with dual diagnosis is largely non-existent. This study aims to investigating the extent of antipsychotic polypharmacy dual diagnosis patients during hospitalisations.Methods: Utilizing cohort data from an integrated dual diagnosis in-patient facility from patients hospitalized between 1 March 2012, to 31 December 2016, we compared the mean antipsychotic medication administered at admission and discharge and examined covariate associations with logistic regressions.Results: The study identified 907 hospital admissions, of which 641 were the first for each patient during the period. At admission, 74.1% received antipsychotics; polypharmacy spanned psychiatric disorders. categories. Patients with affective or personality spectrum disorders were less likely to have antipsychotic polypharmacy upon admission compared to those with psychosis spectrum disorders. 2013-2016 admissions presented less polypharmacy than 2012. Mean antipsychotic numbers remained unchanged for >30-day hospitalizations. Patients admitted without antipsychotic polypharmacy with an affective spectrum disorder or aged 41-50 or over 51 years old were less likely to be discharged with antipsychotic polypharmacy when compared to patients with psychosis spectrum disorder or aged 18-30 years old.Conclusion: Approximately three-quarters of admitted patients were treated with antipsychotic medication. Antipsychotic polypharmacy was observed across all psychiatric disorder categories, indicating potential off-label use. Addressing antipsychotic polypharmacy during treatment is challenging, even for specialised facilities. Rational antipsychotic prescribing, deprescribing protocols, and further prescription pattern research are needed.