The incidence of dementia‐related psychosis in people with dementia: Results from a survey of 302 U.S. healthcare providers

Abstract Background In the U.S., the incidence of dementia‐related psychosis (i.e., hallucinations and delusions) among people with dementia has been estimated at 30%.1‐15 However, it is hypothesized that the lack of a diagnostic code and approved medications for dementia‐related psychosis has resulted in considerable under‐recognition of the symptoms. It is possible that the actual incidence of dementia‐related psychosis is much higher than 30%. Method 302 U.S. healthcare providers (HCPs)—physicians, nurse practitioners, and physician assistants—completed an online survey in which they were asked to estimate the percentages of their patients with dementia who have (a) hallucinations and/or delusions; (b) neuropsychiatric symptoms not including hallucinations or delusions (e.g., aggression, agitation, depression, sleep disturbances, anxiety); or, (c) no neuropsychiatric symptoms. Survey respondents were also asked to provide medical chart data for the last 8 (n=2416) treated patients with dementia and neuropsychiatric symptoms. HCPs were asked several questions about each chart, including which specific neuropsychiatric symptoms the patient had at the last consultation. As part of the data analysis, the percentage of the 2416 charts in which the patient had hallucinations, or delusions, or both, was computed. Result The mean percentages of patients with dementia who had: (a) hallucinations and delusions; (b) neuropsychiatric symptoms not including hallucinations or delusions; and, (c) no neuropsychiatric symptoms, were (a) 44%, (b) 36% and (c) 20% respectively. When asked in the survey to only consider the dementia population with any neuropsychiatric symptoms the HCPs’ estimate of delusions and hallucinations was 55% (calculated as 44%/(44%+36%)). Based on the medical charts, 57% of patients with dementia and neuropsychiatric symptoms had hallucinations and/or delusions, which is close to the HCP’s estimate of 55%. Conclusion U.S. HCPs estimate that 44% of their patients with dementia have hallucinations and/delusions—an incidence much higher than the previously assumed one‐third. Results from a large sample of medical charts attest to the accuracy of the HCPs' estimate.