There are said to be 50 million people living with dementia globally and this is expected to triple by 2050.
Research conducted by Dr Hwajin Yang, Associate Professor at Singapore Management University, and colleagues, examines how the risk of developing dementia is affected by one’s sense of loneliness and sense of control.
Read the original paper: https://doi.org/10.1080/07317115.2020.1799891
Hello and welcome to Research Pod. Thank you for listening and joining us today.
Today we are exploring research related to the psychological mechanisms that may modify the risks of dementia in older adults. Research conducted by Dr Hwajin Yang, Associate Professor at Singapore Management University, and colleagues, examines how the risk of developing dementia is affected by one’s sense of loneliness and sense of control.
There are said to be 50 million people living with dementia globally and this is expected to triple by 2050. Dementia is therefore of great public concern due, in part, to this increase in prevalence, but mainly the impact it can have on a person’s sense of self and ability to achieve quality of life. People with dementia may have problems with remembering, thinking, and speaking. They may say and do things that seem strange to others and they may find everyday tasks more difficult. For some, they may not even seem to be like the person they used to be. People with dementia, though, ask us to remember they are still the same person inside –with all their personal hopes, emotions, and desires.
Dementia is caused by brain cell death, which may occur through a variety of risk factors. As our brains control everything we think say and do – and of course our memories – there are many psychological and social changes that occur on the individual’s dementia journey, such as isolation and loneliness.
People with dementia and their carers all identify loneliness as part of their journey, increasing as the disease progresses. Loneliness is generally considered to be a personal experience of being isolated and an inability to engage with others socially. Loneliness is a crucial risk factor for cognitive decline and dementia. It is a complex concept influenced by subjective and objective experiences. Objectively, it includes the size of a person’s social network and frequency of contact with others, and subjectively, the extent of fulfilling relationships and access to help from others.
Loneliness has been found to occur at the same time as a weakened sense of control, with both having an impact on dementia risk.
This has led Dr Hwajin Yang, Associate Professor at Singapore Management University, and colleagues to investigate the degree to which feelings of loneliness, and the knock effect those feelings have on one’s risk of developing dementia, can be mediated by one’s sense of control. Their hope is that ongoing research will provide insight into the relationship between loneliness and dementia risk. Further to this, they ask if working memory capacity moderates the relationship between beliefs about control (i.e., sense of control) and dementia risks in older adults.
Working memory is a fundamental part of the brain’s executive function. This is a core cognitive resource that enables the mental processing and memory processing that underlie most cognitive tasks, such as problem solving, reasoning, learning, and comprehension. Beliefs in control in healthy older adults are positively related to various cognitive processes associated with working memory. Sense of control is also determined to have two sub sets; personal mastery and perceived constraints, which the team from Singapore Management University and Ehwa Womens University in Korea also explored.
Yang and her colleagues wanted to find out what affected the mental journey from loneliness, known in this model as ‘the focal predictor’, to increased dementia risk, or ‘the criterion’.
They were particularly interested in the impact of sense of control, ‘the mediator’, and working memory, ‘the moderator’, on this process given their understanding that these are also influential in dementia risk.
To uncover the interplay between these factors, Yang and colleagues used a quantitative research method called a ‘second order moderated mediation model’ to explore what influences the mental journey from perceived loneliness to dementia risk via sense of control.
To put that in the context of Dr Yang’s investigation, the second-order moderated mediation means that the moderator influences the relation between the mediator (in this case, one’s sense of control) and criterion (here, their dementia risk).
Dementia risk is hugely complicated with research demonstrating there are a vast number of factors (or, covariant factors) involved, including age, sex, education, income, marital status, number of chronic diseases, intelligence, neuroticism, and depression.
Therefore, in terms of the statistical model used by Yang and her colleagues, these covariant factors were controlled for so they can accurately estimate the mediating effect of sense of control and moderation effect of working memory on the relation between sense of control and dementia risk. This was undertaken through a host of self-reported questionnaires, a couple of working memory and nonverbal reasoning tasks.
Several statistical tests were applied to the huge amount of data created, confirming the surveys’ validity and reliability, and to establish the relationships between all the elements of the model with loneliness as the initial focus, then with sense of control. Mediation analysis was then undertaken to assess whether the relation between loneliness and dementia risk can be accounted for by sense of control. The team also conducted separate mediational analyses with respect to the two facets of sense of control (personal mastery and perceived constraints) to examine whether they would differentially affect the mediational pathway from loneliness to dementia.
They found a significant indirect effect for sense of control. In other words, participants’ sense of control was influencing the impact of loneliness on dementia risk. The sense of control subsets had differing results; personal mastery (i.e., belief in self-efficacy) did not significantly mediate the relation between loneliness and dementia risk, but perceived constraints did.
These results indicate that the relationship between loneliness and dementia risk is driven by a sense of control in overcoming various constraints in everyday life.
Further, a second-order moderated mediation analysis revealed a significant interaction between sense of control and working memory. This provides the understanding that if an individual’s working memory was poor, their sense of control over constraints significantly influences dementia risk. However, if an individual’s working memory is high, one’s sense of control over constraints does not influence dementia risk. As such, one can safely assume that maintaining working-memory capacity can serve to protect individuals with a lower sense of control from increased dementia risk.
In conclusion, the work of Dr Yang and colleagues demonstrates that feelings of loneliness in healthy older adults are indirectly linked to elevated risk of dementia via sense of control over obstacles that interfere with the attainment of goals (i.e., perceived constraints). The influence of their sense of control on dementia risk is contingent on working memory capacity.
There are important clinical implications that can be drawn from this study’s findings:
One, it is important to ensure healthy socioemotional support for older people. This could improve their sense of control when dealing with constraints and challenges.
Two, evidence-based cognitive training of working memory and greater cognitive engagement for older adults could protect against cognitive decline and dementia risk in later life. Whilst the experience of dementia can be devastating, people can still live well with these diseases when recognised as being individuals attempting to find meaning, purpose and love within a confusing world. Research is also generating hope that prevalence can be prevented from exploding as predicted.
In all Dr Yang states “Our findings underscore the critical role of control beliefs and working memory in protecting lonely elderly citizens against their increased dementia risk” and “have implications for intervention programs that target alleviating dementia risk and promoting healthy aging in older adults”.
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