Subjective Cognitive Complaints and Dementia

06 Aug 2019

CHeBA Blog: Subjective Cognitive Complaints and Dementia, Dr Katya Numbers


Study Co-Ordinator of CHeBA’s Sydney Memory & Ageing Study, Dr Katya Numbers, was invited to present on participants’ subjective experience of cognitive decline at the 4th Annual Australia Dementia Forum 2019 Conference (ADF) in Hobart in June.

The Sydney Memory and Ageing Study began in 2005 to examine clinical characteristics and prevalence of mild cognitive impairment and to determine the rate of change of cognitive function over time. Since its inception, the study has included over 1,000 older adult Sydney residents making it one of the largest longitudinal studies of ageing in Australia.

Dr Numbers, who is also a Postdoctoral Fellow with CHeBA and has a PhD in Cognitive Science and a Master of Science in Cognitive Psychology, explains that currently, subjective cognitive complaints are a core criterion in the diagnosis of mild cognitive impairment, which is generally considered a transitional phase between normal cognitive ageing and dementia.

“Despite subjective cognitive complaints being required for an early dementia diagnosis, there remains debate about their actual relationship with cognitive function and decline,” says Dr Numbers.

“That is, some studies have shown there is a relationship while others have found there is not. Differences in results across studies makes understanding whether and how these complaints should factor into a clinical diagnosis of early dementia challenging,” she says.

At the Australian Dementia Forum, which is hosted by the NHMRC National Institute for Dementia Research (NNIDR), Dr Numbers showcased cross-sectional data from the inaugural year of the Memory & Ageing Study (baseline) as well as longitudinal data from year 6 of the study.

“At baseline, we found that participants’ subjective cognitive complaints were not related to their actual performance on neuropsychological tests or their current clinical diagnosis,” explained Dr Numbers.

“However, we were able to predict who would convert from normal cognition or mild cognitive impairment to dementia six years later based on participants’ baseline subjective cognitive complaints,” she said.

Dr Numbers argued that some of the ambiguity about whether these complaints are really a marker of preclinical dementia is due to the cross-sectional nature of many studies. However, when examined longitudinally, a reliable association between subjective cognitive complaints and cognitive decline is often observed. And, the further out from baseline, the more predictive they become.

Having the chance to speak to consumers, their families and their carers about the research process from their point of view was really eye opening. I had not experienced this before in a conference setting and these conversations were the highlight of my time in Hobart.

Dr Katya Numbers

Dr Numbers’ key message for the audience was: “Doctors and clinicians should be listening to what older adults are telling them about their own memory, because they have insight into changes that are occurring that we might not be able to detect right away”.

Following the presentation, an individual living with dementia from the audience raised her hand for a comment. She explained that she was glad to see researchers urging doctors to listen to what older people are telling them about their subjective experience of decline. “I was sick to death of being told I was a ‘worried well’ by doctors. And look, it turns out I was right! I wish someone would have listened to me back then”. Having the opportunity to interact with and get feedback from individuals living with dementia is a unique opportunity for researchers and policy makers alike.

Dr Numbers said that having the opportunity to liaise directly with consumers and their families regarding what it feels like to participate in CHeBA’s research projects was enlightening.

“My passion lies in understanding stigmas around, and perceptions of, older adults’ memory abilities and I have a keen interest in promoting the benefits of a focus on positive ageing,” she said.

“Many of the things I heard from consumers evoked new understanding and got me thinking about how we can incorporate their input into CHeBA’s Memory & Ageing Study in the long term,” said Dr Numbers.