Younger adults diagnosed with frontotemporal dementia face the poorest survival of all early-onset dementia types, with median life expectancy of just under 7 years, according to new Finnish population data that expose the devastating toll of dementia in the prime of life.
The decade-long cohort study, published in the Journal of Neurology, Neurosurgery & Psychiatry [link here], examined every dementia diagnosis made before age 65 across two university hospital districts in Finland. Researchers validated 794 early-onset dementia (EOD) cases and matched each with 10 controls from the general population by age, sex and region. They found all-cause mortality was more than six times higher in the early-onset group.
Survival varied substantially by dementia subtype. While patients with early-onset Alzheimer’s disease lived a median of 9.9 years from diagnosis, those with frontotemporal dementia (FTD) or α‑synucleinopathies such as dementia with Lewy bodies and multiple system atrophy had far worse outcomes – at 6.9 and 7.0 years respectively. The mortality risk was particularly stark for people with FTD, who were 13.75 times more likely to die than their matched controls.
“Mortality rates were significantly affected by the specific EOD diagnosis,” the authors wrote. “FTD and α‑SYNU groups had the shortest survival,” with particularly poor outcomes in FTD-ALS patients.
Despite these stark figures, researchers noted that early-onset dementia still receives little attention in healthcare planning, despite its disproportionately high impact on patients, families and health systems.
“Younger adults are often still in employment and supporting families at the time of diagnosis,” they said. “The impact on life expectancy is even greater than in older patients.”
The study also found that common chronic conditions further worsened outcomes. A history of diabetes, cardiovascular disease, cancer, or chronic pulmonary disease all independently increased mortality. However, the authors stressed that the dementia diagnosis itself remained the dominant risk factor.
“Although survival time in years appears shorter in older patients, the impact of dementia diagnosis to all-cause mortality is more significant in the EOD age group than in the late-onset patients when compared with the general population,” the researchers wrote.
Education level also emerged as a powerful modifier. Patients with tertiary education had a 43% lower risk of death than those without. The authors noted this could reflect the protective effects of cognitive reserve, though the relationship between education and survival remains complex.
“Higher level of education associated with reduced mortality risk,” they wrote, while also acknowledging that this effect may be more pronounced in the general population than in individuals already experiencing progressive cognitive decline.
They also explored genetic and familial contributions to prognosis. While autosomal dominant inheritance (Goldman score 1) was linked to significantly increased mortality, a positive family history of psychiatric illness had no apparent effect. Meanwhile C9orf72 status – the most common genetic mutation in FTD – was also not associated with survival in this cohort.
The study’s population-based design, comprehensive clinical validation and long follow-up add weight to its findings. All patients under 65 with suspected dementia in the included Finnish regions are referred to specialised memory clinics, allowing for near-complete case capture and rigorous diagnostic classification.
Researchers said accurate, up-to-date data on EOD survival were “crucial in designing healthcare structures, comprehensive patient care and clinical trials,” adding that younger adults with dementia are typically still working, parenting and contributing economically when their diagnosis upends every aspect of life.
Despite accounting for about 5% of all dementia cases worldwide, early-onset disease remains largely invisible in health policy, the authors cautioned. They argue that national data systems – such as the Finnish registry model that enabled near-complete case capture in this study – are essential for improving clinical services and policy planning.
“Accurate survival estimates help clinicians plan care and help policymakers allocate resources to the group that needs them most,” the team concluded. “For younger adults with dementia, the impact on life expectancy is even greater than in older patients.