Social Isolation and Dementia
Episodic memory is the recollection of past experiences associated with a particular time and place. It is the type of memory that shows dramatic decline in Alzheimer’s dementia. Individuals older than 80 with episodic memory as good as that of middle-aged adults are likely to report high levels of psychological well-being, and demonstrate strong social relationships. A recent study using the Ryff 42-item psychological well-being questionnaire revealed that older individuals without episodic memory loss had significant higher scores in the area of positive relations with others. The survey also assessed individuals’ level of autonomy, environmental mastery, personal growth, purpose in life, and self-acceptance.
Other longitudinal studies have shown that higher level of social activities and social integration are associated with better cognitive function. Perceived social support is more important than the size of the social network in preserving cognitive function. Having supportive relationships seems to improve problem-solving abilities and processing efficiency rather than memory storage.
Other studies showed an association between dementia and reduced participation in leisure activities in midlife, especially leisure activities that involve others. The Bronx aging study followed a cohort of individuals who had no dementia at baseline over a median of 5 years and up to 21 years. Using clinical details and neuropsychological evaluations it was able to show that dementia developed in 27% of adults (124/469) over 5.1 years. Individuals with dementia were older, had lower levels of education, and significantly lower scores on the cognitive activity scale. They had similar rates of physical activity to those who did not develop dementia. Activities such as reading, playing board games, and playing musical instruments were associated with lower risk of dementia. Dancing was the only physical activity associated with lower risk of dementia.
Similarly, a French cohort study found that knitting, doing odd jobs, gardening, and traveling reduced the risk of dementia. Many of these activities requires some interaction with others. No study thus far has been able to establish a causal relation between participation in leisure activities and dementia, nor has it been established that the duration of the leisure activity is important. One could argue that reduced participation in leisure activities may be an early marker for declines on cognitive tests. In any case, it seems clear that participation in leisure activities is a behavior that promotes health.
 Cook Maher A, Kielb S, Loyer E, et al. Psychological well-being in elderly adults with extraordinary episodic memory. PloS One. 2017;12(10):e0186413.
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 Verghese J, Lipton RB, Katz MJ, et al. Leisure activities and the risk of dementia in the elderly. N Engl J Med 2003; 348(25): 2508-2516.
 Fabrigoule C, Letenneur L, Dartigues JF, et al., Social and leisure activites and risk of dementia: a prospective longitudinal study. J Am Geriatr Soc 1995;43:485-90.
[JKO1]What did it find?