The survival rates for individuals diagnosed with early-onset dementia—defined as dementia diagnosed before the age of 65—vary significantly depending on the clinical type of the disease. This finding emerges from research published in the Journal of Neurology, Neurosurgery & Psychiatry. Interestingly, factors such as sex, age, family history, and co-existing conditions do not appear to be specific risk factors for early-onset dementia.
While dementia in older age groups is known to reduce survival times, the impact on mortality risk is even more pronounced in those with early-onset dementia compared to their peers. Globally, about 5% of dementia cases are classified as early onset. Despite its recognition as a life-limiting condition among the elderly, few studies have focused on survival times and prognostic factors for early-onset dementia, according to the researchers.
Research Methodology and Findings
To delve deeper into this issue and enhance treatment and care strategies for early-onset dementia patients, researchers analyzed data from 12,490 visits to dementia outpatient clinics in two Finnish university hospital districts between 2010 and 2021. They identified 794 confirmed cases of early-onset dementia, including Alzheimer’s disease, frontotemporal dementia, alpha-synucleinopathies (notably, Lewy body dementia), and mixed or other forms of dementia, such as vascular cognitive impairment.
The survival times for these patients were compared with those of 7,930 individuals without neurodegenerative disease, matched for age, sex, and geographical region, using general population data registers. During the study period, 215 individuals with early-onset dementia died, with an average survival time of nearly nine years. However, survival times varied by disease subtype.
Frontotemporal dementia and Lewy body dementia had the shortest average survival time of nearly seven years, while those with both frontotemporal dementia and motor neurone disease (ALS) lived just over two years on average.
In contrast, individuals with Alzheimer’s disease had an average survival time of nearly ten years, and those with vascular cognitive impairment lived the longest, averaging over ten years.
Comparative Mortality Rates
When compared to individuals without neurodegenerative diseases, the mortality rate from any cause was more than 6.5 times higher among those with early-onset dementia. The risk was particularly elevated for specific subtypes, with frontotemporal dementia patients facing nearly 14 times the mortality risk, and those with vascular cognitive impairment experiencing more than four times the risk.
While factors such as male sex, older age, co-existing conditions, and lower educational attainment were associated with an increased risk of death, these were not specific to early-onset dementia. The diagnosis of early-onset dementia itself was the strongest independent predictor of survival time. Diabetes, a known dementia risk factor, was associated with shorter survival times among early-onset dementia patients.
“Overall, although the survival time in years appears shorter in older patients, the impact of dementia diagnosis on all-cause mortality is more significant in the [early onset dementia] age group than in the late onset patients when compared with the general population,” comment the researchers.
Study Limitations and Implications
This observational study does not establish causation, and the researchers acknowledge limitations, including the lack of genetic or neuropathological confirmation for most participants and the small numbers in each clinical subgroup. Despite these limitations, the study provides valuable insights into early-onset dementia survival rates within a validated population-based cohort, highlighting the substantial effect of the diagnosis on patient mortality.
Accurate and current data on survival and mortality rates for early-onset dementia are crucial for designing effective healthcare structures, comprehensive patient care, and clinical trials. As the research community continues to explore this challenging condition, these findings underscore the importance of tailored approaches to treatment and care for those affected by early-onset dementia.
