Objective: To assess how well the content of clinical outcome assessments (COAs) for psychosis in Parkinson’s Disease (PD) aligns with the 2008 International Parkinson and Movement Disorders Society (MDS) Task Force guidance and to synthesise evidence on their validity, including the diversity of populations in validation cohorts.
Background: PD psychosis affects 60% of patients during their lifetime. It is associated with poor patient outcomes, including increased nursing home admissions and higher levels of carer distress. Lewy Body Dementia (LBD) is a related condition differentiated by the chronology of symptom onset but otherwise comparable symptoms. In 2008, the MDS task force found no COA with full content validity for PD psychosis.
Method: We searched PubMed, Embase, and PsycINFO databases from January 2008 to January 2026 for studies using COAs to assess psychosis in people with PD and Lewy Body Dementia. We evaluated content validity against PD psychosis diagnostic criteria (illusions, sense of presence, hallucinations, and delusions); and risk of bias and evidence quality using COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidance.
Results: Sixty-four unique COAs were identified from 243 eligible studies. Of the 17 studies that reported participants’ ethnicity, 81% were White. Nine identified COAs assessed all four symptom domains, indicating content validity, but all were rated as having high risk of bias, so they did not meet the criteria for recommendation as adequate measures of psychotic symptoms for people with PD psychosis in any population.
Conclusion: There was no singular COA that can currently be recommended to assess psychosis in PD. Pending further validation studies, assessment batteries may be the most pragmatic choice. There is a paucity of evidence for any psychosis COA in non-White populations with PD.
To cite this abstract in AMA style:
E. Camboe, S. Delray, MHS. Tosin, AJ. Noyce, C. Cooper. Clinical Outcome Assessments for Parkinson’s Disease Psychosis: A Systematic Review [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/clinical-outcome-assessments-for-parkinsons-disease-psychosis-a-systematic-review/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/clinical-outcome-assessments-for-parkinsons-disease-psychosis-a-systematic-review/