Down syndrome has a prevalence rate in the UK of 1.08 per 1000 live births (Morris & Alberman, 2009) and the Downs Syndrome Association (DSA) estimate that there are over 40,000 people in the UK with Down syndrome.
Typically, a person with Down syndrome is at increased risk from a number of health conditions and it is important to have effective health monitoring from birth to old age.
People with Down syndrome are at a relatively high risk of developing Alzheimer’s dementia, and at an earlier age than would normally be expected (Strydom et al., 2010).
It is important to understand the trajectory of dementia to ensure the most effective support for people with Down syndrome.
In this study, Wark, Hussain and Parmenter (2014) report three case studies of individuals with Down syndrome who were diagnosed with dementia but then returned to normal daily functioning after a major life event, before displaying a severe decline in functioning.
The premise for the study was based on the observation of a nongovernment disability organisation that identified three separate cases, which appeared to indicate a phenomenon connected to the trajectory of dementia in Down syndrome.
They reported that two men and one woman with Down syndrome and a diagnosis of dementia experienced an observable decline of functioning consistent with dementia but then experienced a ‘bounce-back’ and appeared to return to levels of daily functioning similar to their pre-diagnosis functioning.
The authors evaluated the case history of these three individuals with Down syndrome to establish the timeline of dementia and functioning levels with a view to exploring whether there were any shared characteristics that may be related to this unusual dementia trajectory.
They used a descriptive case study approach reviewing all case files and interviewing key staff members.
The authors note several similarities between the three individuals. Prior to the diagnosis of dementia, they were all reported to have high levels of personal skills, which declined to lead to the diagnosis in their late 40s or 50s.
After the diagnosis of dementia, they all experienced a significant life event that was followed by an increase in functioning to pre-diagnosis levels, which was maintained for at least six months.
They then experienced a quick and unexpected decline in functioning to levels lower than that at the initial diagnosis of dementia.
The researchers pay particular attention to the ‘significant life event’. They note that although the life events may not have been positive initially, they all resulted in a long-term positive outcome, for example increased opportunities for socialisation with peers.
The authors suggest that the initial diagnosis of dementia may not have been correct or the dementia appeared more severe than it was, and instead the decrease in functioning reported before the diagnosis of dementia may have been largely due to undiagnosed depression.
The life event is hypothesised to have ‘broken’ the depression and therefore accounts for the apparent rebound in functioning. The individuals’ subsequent decline is thought to be accounted for by dementia, as may be expected from their age and type of learning disability.
The authors conclude that the observation of this unique dementia trajectory in Down syndrome warrants further research, with particular emphasis on establishing appropriate interventions to better support people with Down syndrome and dementia.
They suggest that the assessment of dementia in Down syndrome may be unreliable, possibly because clinicians are aware of the high incidence of dementia in Down syndrome. They also highlight that depressive symptoms may need to be more proactively identified and treated to improve the quality of life for people with Down syndrome.
Strengths and limitations
The authors note that there have been reports of this phenomenon elsewhere in the literature and that it has been reported anecdotally in other countries. However, as the authors acknowledge, this is a small scale study and there remains the possibility that these cases are coincidences.
Despite this, it is valuable to publish such case studies in the scientific literature so potentially important observations are not missed and can explored by further research.
Further information about the non-government disability organisation, the individuals with Down syndrome and the data gathered would have been valuable.
The authors note that key information such as quantitative measures of intellectual level and functional assessments was limited. In particular, further information is needed about the significant life events as the authors’ conclusions are heavily based on their importance. It would also be interesting to know whether other people with Down syndrome and dementia involved with the non-government disability organisation experienced similar life events but did not experience a subsequent increase in functioning.
Although it would be informative to know more about the organisation, and the authors’ relationship with the organisation, it is promising to see such synergy between research and practice. An unusual pattern in the dementia trajectory was observed in practice and this was then explored in more detail by researchers and reported so that an area of literature can be furthered and knowledge can be shared.
The link to depression is speculative and is not based on convincing evidence gathered from the case reviews or the existing literature.
None of the three individuals was diagnosed with depression, although many mental health problems go undiagnosed. However it is important to raise questions about the diagnosis and trajectory of dementia and depression in people with Down syndrome, and whether this differs from the general population and other people with learning disabilities.
The authors’ conclusions have potentially very significant clinical implications. Some symptoms related to a decline in functioning can be attributed to dementia or depression, for example withdrawal, low energy levels and sadness, and therefore it is important for clinicians to consider the possibility of depression when assessing for dementia (Jensen & Bulova, 2014).
However further evidence is needed to confirm the authors’ speculation about undiagnosed depression in Down syndrome and how it may affect dementia diagnoses.
A prospective large-scale longitudinal study is needed, to monitor adults with Down syndrome before the likely onset of dementia to establish baseline functioning and then to monitor the trajectory of dementia, functioning and depression and recording all major life events.
The study also highlights the need for regular health monitoring by health professionals. The study was conducted in Australia, and the authors note that services are beginning to establish baseline functioning of adults with Down syndrome over the age of 35 through annual screening.
In the UK, annual health checks for people with learning disabilities are being promoted, and this would offer a good opportunity to improve health monitoring for people with Down syndrome and screen for depression and dementia at regular intervals.
Wark, S., Hussain, R., & Parmenter, T. (2014). Down syndrome and dementia Is depression a confounder for accurate diagnosis and treatment?. Journal of Intellectual Disabilities, 18(4), 305-314. [abstract]
Jensen, K. M., & Bulova, P. J. (2014). Managing the care of adults with Down’s syndrome. BMJ, 349 [abstract] [LD Elf post]
Morris, J. K., & Alberman, E. (2009). Trends in Down’s syndrome live births and antenatal diagnoses in England and Wales from 1989 to 2008: analysis of data from the National Down Syndrome Cytogenetic Register. BMJ, 339, b3794. [abstract]
Strydom, A., Shooshtari, S., Lee, L., Raykar, V., Torr, J., Tsiouris, J., Jokinen, N., Courtenay, K., Bass, N., Sinnema, M. & Maaskant, M. (2010), Dementia in Older Adults With Intellectual Disabilities—Epidemiology, Presentation, and Diagnosis. Journal of Policy and Practice in Intellectual Disabilities, 7, 96–110. [abstract]
Today @silvana_mengoni has published her debut blog on the trajectory of dementia for people with Down syndrome http://t.co/EbewIXvJnW
1/2 @LearningDisElf @ukatnews @silvana_mengoni this is a really tiny number study – 2draw any meaningful conclusions the study group would
2/2 @LearningDisElf @ukatnews @silvana_mengoni need 2 b much larger & gr8er understanding of “signif life events” 2 b known.
1/2 @LearningDisElf @ukatnews @silvana_mengoni i would ? that this was evid of dementia – sounds more like reaction to signif life event
2/2 @LearningDisElf @ukatnews @silvana_mengoni tho i acknowledge that ppl with DS have higher risk for alzheimers. A bigger study wd be gr8
@Init4Health @LearningDisElf @ukatnews Agree. Interesting findings but need a bigger study to explore further & draw conclusions
@silvana_mengoni @LearningDisElf @ukatnews 4sure larger numbers required – it would b valuable study esp as ppl with ds now living longer
@silvana_mengoni @LearningDisElf In Herts CLDNs screen DS from 30 using DLDs & look at life events & discuss at monthly memory service MDT
My debut blog! RT @LearningDisElf: Trajectory of dementia: is it different for people with Down syndrome? http://t.co/xz8ek1jxAI
The authors conclude that the observation of this unique dementia trajectory in Down syndrome warrants further… http://t.co/jN4aXpGs75
Awesome entry to the blogosphere by @silvana_mengoni about trajectory of dementia in DS on @LearningDisElf today. http://t.co/FGvcKUNJCC
Unique dementia trajectory in Down syndrome warrants further research http://t.co/EbewIXvJnW
Laura Dinnen xx
Thanks hun xx
I reckon we would pick this up in our service. What do you think Deborah Green Sara Parsons ?
“@LearningDisElf: Unique dementia trajectory in Down syndrome http://t.co/y7xMkKvyPn” @rozangier we’d pick this up, I reckon/hope!
@yardsoflard @LearningDisElf this is so interesting. I am curious abt the significant life events tho? Need some single case studies
@rozangier @LearningDisElf yes I wondered about that. Maybe moving to a new house that suits them better?
@yardsoflard @LearningDisElf that makes sense
@rozangier @LearningDisElf Could also be death of someone after long and stressful illness. May or may not lift mood I guess!?
@yardsoflard @LearningDisElf exactly what happened in case I mentioned. With mum 24/7, mum dies, all signs of confusion and distress go.
@rozangier @LearningDisElf oh dear. Sad situation. Perhaps he’s your single case study.
@yardsoflard @LearningDisElf it was v sad. V loving family. She could be. She is doing v well now.
@yardsoflard @LearningDisElf seen depression so severe I was sure it was dementia. Think we are more aware of diagnostic overshadowing now.
Don’t miss: Trajectory of dementia: is it different for people with Down syndrome? http://t.co/EbewIXvJnW #EBP
Speaking as a husband/carer and not a professional I think this study, being just about three people seems interesting but not that significant but it’s encouraging to be talking about it. For everyone with an intellectual disability the individual variations and resulting effects of their disability will no doubt be unique and often very subtle so very hard to diagnose a specific cause I am sure. My wife (mild/moderate LD) was diagnosed with early onset dementia last year by our community LD team who did a very thorough job and even then they could only say that dementia is only a likely cause of her slowly deteriorating abilities.
RT @Mark_Sheldon: Trajectory of dementia: is it different for people with Down syndrome? http://t.co/HdxNVZSvvn via @LearningDisElf http:/…
Trajectory of dementia: is it different for people with Down syndrome? http://t.co/V1dCwBFfWD via @sharethis
I am a dementia specialist nurse and have been assessing people with down’s syndrome using a number of assessment tools. I can say that these assessmnet tools if used correctly do pick up on the clinical symptoms of dementia
thanks for your comment. Good to hear about your work and the use of assessment tools. I think the article and the blog about it are both aiming to continue to raise awareness about dementia and focus people’s attention on a range of signs