TOPLINE:

Early-onset dementia (EOD) significantly affected patients' survival, with frontotemporal dementia showing the poorest prognosis. The risk for mortality was independently associated with patients' sex, age, history of diabetes, and autosomal dominant family history.

METHODOLOGY:

• Researchers conducted a population-based cohort study to evaluate survival and mortality rates in a large and comprehensive EOD cohort encompassing all major dementia subtypes.
• The cohort included 794 newly diagnosed cases of EOD, including of Alzheimer's disease, frontotemporal dementia, alpha-synucleinopathy (α-SYNU), and other EOD spectra, from two defined regions in Finland. All included patients were diagnosed with dementia before or at the age of 65 years.
• All cases of EOD were compared with region-, age-, and sex-matched control groups without neurodegenerative diseases.

TAKEAWAY:

• The median survival time from EOD diagnosis to death was 8.7 years, with the frontotemporal dementia group having the shortest median survival time (6.9 years), followed by the α-SYNU group (7.0 years) and the Alzheimer's disease group (9.9 years).
• Compared with the matched control group, the frontotemporal dementia group had the highest risk for all-cause mortality (hazard ratio [HR], 13.75), followed by the α-SYNU (HR, 7.85), Alzheimer's disease (HR, 4.62), and other EOD (HR, 4.39) groups (P < .001 for all).
• The risk for mortality was 3.02-fold higher in the frontotemporal dementia group and 2.68-fold higher in the α-SYNU group than in the Alzheimer's disease group (P < .001 for both).
• Male sex, older age at diagnosis, a history of diabetes, and a family history of dementia were independently associated with an increased risk for mortality.

IN PRACTICE:

"Our study provides up-to-date survival rates in EOD, and highlights the substantial effect caused by EOD diagnosis to patients' mortality," the authors wrote.

SOURCE:

This study was led by Kasper Katisko, Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland. It was published online on November 04, 2025, in the Journal of Neurology, Neurosurgery & Psychiatry.

LIMITATIONS:

This study included a limited number of neuropathologically confirmed or definite diagnoses. Small subgroup sizes limited the statistical power for some subgroup analyses.

DISCLOSURES:

This study received funding from multiple organisations, including the Finnish Brain Foundation, Finnish Medical Foundation, and Finnish Parkinson Foundation. Two authors reported serving on advisory boards and as consultants and/or receiving honoraria for lectures from various pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.