Antipsychotic treatment patterns and predictors of polypharmacy in psychotic disorders: 20-year real-world data from...

Antipsychotics are the cornerstone of psychotic disorder treatment, often used in combination with other psychotropics. However, real-world data on inpatient treatment in Türkiye remain scarce.

This study aims to investigate the clinical characteristics, hospitalization features, and psychotropic treatment patterns of inpatients diagnosed with psychotic disorders.

This retrospective, cross-sectional pharmacoepidemiological study examined treatment patterns and predictors of antipsychotic polypharmacy (APP) among 934 patients (1241 hospitalizations) diagnosed with psychotic disorders at a university psychiatry clinic in Eastern Türkiye between 2001 and 2021.

The sample included 35.8% females and had a mean age of 34.03 ± 11.01 years. APP (use of ≥ 2 antipsychotics) was identified in 37.7% of cases, being significantly more frequent in males, those aged 55-65, schizophrenia (SCH) patients, and post-2012 hospitalizations. Atypical antipsychotics were prescribed in 95.25% of cases, and the most common APP pattern was atypical-atypical combinations (52.5%). Olanzapine (33.04%), risperidone (27.88%), and quetiapine (19.58%) were the most frequently prescribed agents. Mood stabilizers and antidepressants were used in 25.22% and 14.5% of cases, respectively. Multinomial regression showed that schizoaffective disorder (SAD) was strongly associated with both APP (OR = 3.05) and combined therapy (OR = 20.0), while delusional disorder also predicted combined therapy (OR = 2.4). Longer hospitalization duration and post-2012 admissions predicted APP, whereas outpatient follow-up and medical comorbidities predicted combined treatment. Linear regression revealed that higher PANSS scores predicted longer hospital stays, while hospitalizations in later years were associated with shorter stays.

This study provides one of the most comprehensive longitudinal evaluations of inpatient psychosis treatment in Türkiye and offers valuable insights into prescribing trends, informing future clinical and policy approaches.