A 20-year longitudinal TCD study on dementia in adults with Down syndrome in Ireland has found very high prevalence rates, significantly earlier onset than in the general population and high risk rates for dementia for people with Down Syndrome.
The findings, which were published in the Journal of Intellectual Disability Research have prompted the study’s lead author to call for a range of urgent measures to address the needs of people with Down Syndrome, their families, medical professionals and the care system.
The study followed 77 women with Down Syndrome over the age of 35 years who were enrolled and screened in 1996 and then assessed for symptoms of dementia on an annual basis until death, with assessments completed in a specialist memory clinic at the Daughters of Charity Disability Support Service.
It found that 97.4% of the women assessed developed dementia over the 20-year period. In the general population, the estimated prevalence rates are 5-7% in people aged 65 years and over.
It also found that the risk of developing dementia in people with Down Syndrome is 23.4% at age 50, 45% by age 55 and 88% by the age of 65 - significantly higher than in the general population, which is between 4.3% and 8.6% in people aged 65 years and older.
The study found the average length of survival after developing dementia was 7 years, with some people living with dementia for 20 years. It was previously thought that people with Down Syndrome lived between 3-5 years.
Lead author Professor Mary McCarron said: “We now have the statistics for Ireland, and clearly radical changes need to be made in order to respond and address the needs of this often vulnerable group of people to help diagnose, support, treat and help prevent dementia.
“We need to support people with Down syndrome and dementia to live in the home of their choice with their family or friends for as long as possible.
“Supports should include appropriate dementia specific respite services for family and/or peers in group homes.
“Clinical support and education should be provided to family and staff caregivers. We need tailored dementia specific day programmes and residential options, as well as care approaches which are stress free and environments which are dementia capable.”
