Incidence and course of dementia in people with Down's syndrome: findings from a population-based study.
Personality changes after age 30 in Down syndrome often signal frontal-lobe dementia years before classic Alzheimer's memory loss.
01Research in Context
What this study did
Researchers tracked every adult with Down syndrome in one region. They watched for signs of dementia over many years.
They split the group by age. They counted who got dementia and what kind.
What they found
Adults over 30 showed two patterns. Younger ones got frontal-lobe dementia first. Older ones got classic Alzheimer's.
Personality changes came before memory loss. Families noticed mood swings and odd habits years before forgetfulness.
How this fits with other research
Yuwiler et al. (1992) saw no decline in adults . The new study says watch for changes after 30. The gap is where signs first appear.
McLennan et al. (2008) lists the exact behaviors that trigger referrals: excess tantrums, pacing, and staff burnout. Their list matches the early personality red flags seen here.
Ahlborn et al. (2008) shows one young learners who stayed sharp. That single case reminds us that not every adult with Down syndrome will decline, even though the group risk is high.
Why it matters
Start screening at 30, not 50. Use checklists for sudden mood shifts, new rituals, or social withdrawal. Catch frontal-lobe dementia early and you can plan supports before memory fades.
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02At a glance
03Original abstract
The prevalence rate of Alzheimer's disease (AD) in people with Down's syndrome (DS) increases significantly with age. However, the nature of the early clinical presentation, course and incidence rates of dementia are uncertain. The aims of the present study were to investigate the characteristics of age-related clinical changes and incidence rates for dementia in a population-based sample of people with DS aged 30 years and older at the age of risk for dementia. A modified version of the Cambridge Examination for Mental Disorders of the Elderly informant interview was used to determine the extent and nature of changes in memory, personality, general mental functioning and daily living skill 18 months after a similar assessment At the time of the first assessment, the initial changes reported were predominately in behaviour and personality. At the second assessment, overall estimated incidence rates for frontal-like dementia were high (0.24), mainly in the younger groups, with incidence rates of AD, meeting both ICD-10 and DSM-IV criteria, of 0.04 predominately in the older groups. The present authors have hypothesized that the observed personality changes and the high estimated incidence rates of frontal-like dementia in the younger groups may indicate that functions served by the frontal lobes are the first to be compromised with the progressive development of Alzheimer-like neuropathology in people with DS.
Journal of intellectual disability research : JIDR, 2000 · doi:10.1046/j.1365-2788.2000.00263.x