Patient and Physician Perspectives on Pharmacotherapy in Parkinson’s Disease Psychosis: A Mixed-Methods Exploratory Study

Psychosis is a frequent and disabling non-motor complication of Parkinson's disease (PD). Clozapine and quetiapine are widely used in the treatment of Parkinson's disease psychosis (PDP). We conducted an exploratory study to compare patient experiences with physician prescribing practices. Patients with PDP hospitalized at a university center completed semi-structured interviews on perceived efficacy, adverse effects, and daily functioning. Neurologists and geriatricians attending training sessions completed a structured questionnaire on prescribing patterns, attitudes toward clozapine, and perceived treatment burden. Data were analyzed thematically and triangulated across cohorts. Eleven patients (mean age 81 years; nine treated with quetiapine, two with clozapine) were included. Most quetiapine-treated patients reported persistent hallucinations, sedation, dizziness, and reduced autonomy. Fourteen physicians completed the survey and most preferred quetiapine, citing monitoring logistics and agranulocytosis risk as barriers to clozapine. Overall, patient priorities centered on symptom control and independence, whereas physician decisions emphasized feasibility and safety. Facilitating clozapine monitoring and incorporating patient-reported outcomes into routine care may improve patient-centered PDP management.