The frequency of psychotic symptoms in types of dementia: a systematic review.

The frequency of psychotic symptoms in older adults is high, mainly in neurocognitive cognitions of the most varied etiologies.

Objectives: This study aimed to review the studies that analyze the frequency of the types of delusions, hallucinations, and misidentifications in dementia conditions of different etiologies.

Methods: A systematic review was conducted on August 9, 2021, in the PubMed, PsycInfo, Embase, Web of Science, and Scopus databases with the following descriptors: (dementia OR alzheimer disease OR dementia with Lewy bodies OR frontotemporal dementia OR mixed dementia OR vascular dementia OR major neurocognitive disorder OR parkinson disease dementia) AND (psychotic symptoms OR psychosis OR hallucinations OR delusions OR psychopathology OR misidentification) AND (prevalence OR epidemiology).

Results: A total of 5,077 articles were found, with a final inclusion of 35. The overall frequency of psychotic symptoms ranged from 34 to 63% in dementia conditions of the most varied etiologies. Alzheimer's disease (AD) presents more delusions and hallucinations and has a higher frequency regarding the presence of misidentifications. On the contrary, Dementia with Lewy bodies (DLB) seems to present more hallucinations, even auditory, when compared to the other dementias, concomitantly with delusions. Vascular and frontotemporal dementia present fewer psychotic symptoms than DLB and AD.

Conclusions: We identified a gap in the literature on the description of the psychotic symptoms of dementia, mainly in those of non-AD etiologies. Studies that assess the neuropsychiatric symptoms of dementias deeply might contribute in a more definite manner to the causal diagnosis of dementia.