Characteristics associated with progression to probable Dementia with Lewy Bodies in a cohort with late onset psychosis

Abstract

AbstractBackgroundA psychiatric‐onset prodrome is increasingly recognised in Dementia with Lewy Bodies (DLB) and while late‐onset psychosis is associated with increased risk of developing dementia, it is not clear what proportion of patients with psychotic disorders go onto develop DLB. Among patients with late onset psychosis, we aimed to identify the proportion who developed DLB and to characterise the clinical features and characteristics of those who convert to DLB.MethodAnonymised data collected between 2006‐2021 was retrieved from clinical records from a large London mental health service for patients who were ≥50 years when first diagnosed with a psychotic disorder. Patients with dementia diagnoses >3 months later were identified and a natural language processing (NLP) algorithm was used to identify patients with probable DLB, with two of the core features (visual hallucinations, parkinsonism, fluctuations or sleep disturbance) identified in the free text at the time of dementia diagnosis. Predictors of progression to DLB were investigated including demographic factors, Health of the National Outcome scale for older people (HoNOS65+) and key clinical features at the time of psychosis diagnosis identified with NLP.ResultIn 3784 patients with late onset psychosis, 321 (8.5%) received a diagnosis of dementia from mental health services during the follow‐up period (mean time to dementia diagnosis 3.66±3.13 years). A high percentage (30.5%, n = 98) of those who developed dementia met criteria for probable DLB. Presence of hallucinations, falls, parkinsonism, fluctuations or drowsiness at the time of late onset psychosis diagnosis was associated with an increased relative risk of later developing probable DLB. Adjusted multivariate Cox proportional hazard models suggested that older age and higher scores on HoNOS cognitive and hallucinatory items at baseline were significant predictors of faster progression to DLB.ConclusionDLB is overrepresented in patients with late‐onset psychosis who later develop dementia; a psychiatric prodrome in dementia should give a high index of suspicion for DLB. In patients with late‐onset psychosis, risk factors for future progression to DLB include cognitive impairment, older age, hallucinations, falls, fluctuations, parkinsonism and drowsiness. Where these hallmarks are present at the time of psychosis, close follow up could facilitate the earlier identification of DLB.