Validation of the Psychosis and Hallucinations Questionnaire in Lewy Body Dementia

Background: Psychotic symptoms are common in patients with Parkinson’s Disease Dementia and Dementia with Lewy Bodies, known collectively as the Lewy Body Dementias (LBD). It is important to identify these symptoms early and accurately. However, these symptoms are challenging to identify and quantify in clinical practice. The Psychosis and Hallucinations Questionnaire (PsycH-Q) was developed as a self-report tool using patient-friendly language to assess hallucinations and related phenomena and has been previously validated in Parkinson’s Disease patients without dementia and their caregivers. Objectives: This study aimed to evaluate the utility of the PsycH-Q in patients diagnosed with a Lewy Body Dementia. Methods: A total of 33 LBD patients, assisted by their caregivers, completed the PsycH-Q, along with the Scales for Outcomes in Parkinson’s Disease-Psychiatric Complications (SCOPA-PC) and the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). Items relating to hallucinations and psychotic phenomena from the SCOPA-PC and MDS-UPDRS were then compared with analogous ratings on the PsycH-Q. Results: Scores on the PsycH-Q were significantly correlated with SCOPA-PC Questions 1 and 3, as well as the MDS-UPDRS question 1.2 (Spearman’s rho of 0.65, 0.73, and 0.47, respectively; p < 0.01 for all three correlations). Conclusions: These results support the PsycH-Q as a patient-friendly questionnaire that accurately identifies hallucinatory phenomena and their features in LBD patients via self-report completed by patients with their caregivers. Future use of the PsycH-Q in clinical practice and research could improve early detection of psychotic symptoms in LBD patients, leading to improved management.