Patterns of neuropsychiatric symptoms in primary and secondary tauopathies: Caregiver and patient perspectives

Abstract

Introduction/Aims: Understanding the differences in neuropsychiatric symptoms (NPSs) across tauopathies, particularly in the early stages of the disease, may aid in differential diagnosis. The aims of the research are as follows: a) to examine the patterns of NPSs in primary (frontotemporal dementia - FTD and progressive supranuclear palsy - PSP) and secondary (Alzheimer's disease - AD) tauopathies; b) to examine the differences in NPSs reported by patients and caregivers. Methods: The study included 312 patients, 176 of whom had a disease duration of ≤3 years. The presence of NPSs based on caregiver's report was assessed by neuropsychiatric questionnaire (NPI). Patient's assessment of NPSs was examined by Hamilton's Depression and Anxiety Scales and the Apathy Scale. Results: In AD, the most common and severe neuropsychiatric symptoms are mood disorders and apathy. In contrast, agitation-related symptoms are also prominent in FTD and PSP. The profile of NPSs in FTD and PSP is similar, but irritability and aberrant motor behavior are more pronounced in FTD, while sleep disturbances are dominant in PSP. The prevalence of NPSs reported by caregivers on NPI was higher than that reported by patients. Conclusions: FTD and PSP are characterized by more frequent and more severe NPSs and have distinct psychiatric patterns compared to AD, even in the early disease course. Caregiver's observations of the patient's behavior could be of key importance in distinguishing these tauopathies, particularly in the absence of hard motor and cognitive symptoms in early disease course. Assessments of depression, anxiety, and apathy by patients themselves and their caregivers differ significantly, and data from these two sources cannot be considered interchangeable and comparable.