Examining neuropsychiatric symptoms and functional decline in behavioral variant frontotemporal dementia

Neuropsychiatric symptoms (NPS) are core features of behavioral variant frontotemporal dementia (bvFTD), but their association with functional decline is incompletely understood.

Participants (N = 219) were individuals enrolled in Alzheimer's Disease Research Centers between 2005 and 2024 with early-stage bvFTD (CDR ≤ 0.5). Functional status was coded as a binary variable based on the Functional Activities Questionnaire. Behavioral data were derived from the Neuropsychiatric Inventory Questionnaire and Clinician Judgement of Symptoms. Descriptive statistics and Cox proportional hazard analyses were used to characterize functional impairments and their association with NPS.

Impairments in transactions (47%) and verbal communication (44%) were common at baseline, while impairments in self-care and incontinence (<10%) were rare. Apathy (65%), disinhibition (55%), depression, anxiety, irritability, and agitation were common at baseline (>40%). Psychosis was rare at baseline (<10%). By visit 4, impairments in transactions (81%), meal-preparation (65%), self-care (55%) and verbal communication (61%) were common. Emergence of apathy, disinhibition, depression, anxiety, and irritability were associated with an increased hazard of impairments in ambulation, meal preparation, self-care, and transactions.

NPS in bvFTD are frequent, occur early, and are associated with functional decline. Timely recognition and treatment of NPS may mitigate their impact on function.