High-Quality Relationships May Have Long-Term Protective Effect Against Dementia

Deborah Brauser

October 28, 2010

October 28, 2010 — The quality, not quantity, of social networks may have a long-term protective effect against dementia, new research suggests.

Participants in a large cohort study that included more than 2000 participants older than 65 years showed those who reported being satisfied with their relationships at baseline had a 23% reduced risk of developing dementia from 5 to 15 years later compared with those who were not satisfied.

"The important result for clinicians is that promoting favorable social interactions in elderly people seems to have beneficial impact on cognitive aging," lead study author Hélène Amieva, PhD, researcher in Neuropsychology and Epidemiology of Aging at the University of Bordeaux in France, told Medscape Medical News.

"One could have thought that the more you have social relationships the more you are protected against dementia, but in fact the only social network variables associated with a reduced risk of subsequent dementia or Alzheimer's disease (AD) were those reflecting the quality of relationships," she added.

The study was published online August 31 in Psychosomatic Medicine.

Positive Impact of Rich Social Networks

Dr. Hélène Amieva

Past research has shown that "markers of low social integration are associated with higher mortality, higher incidence of coronary heart diseases, worse prognosis in cancer, and cardiovascular diseases," investigators write.

For psychiatric and neurologic conditions, "rich social networks and efficient social support have often been associated with lower depressive symptoms, better stroke recovery, and lower age-related cognitive decline," they add.

Regarding dementia, Dr. Amieva said that investigating possible prevention techniques has been a huge scientific and medical challenge.

"Promising strategies include vascular risk factor control, promoting cognitive activity, physical activity, or healthy diet habits. Results gathered from epidemiological studies may be important to determine whether promoting social engagement could also be part of such prevention strategies," she explained.

For this study, the investigators evaluated data on 2089 patients (mean age, 73.7 years; 59.9% female) from the PAQUID project, a prospective, population-based study of cognitive aging and dementia in 3777 total participants in France. Study initiation began in 1988.

All participants were evaluated in their homes at baseline and then at 1-, 3-, 5-, 8-, 10-, 13-, and 15-year follow-up. At each visit, they completed a psychologist-administered questionnaire on socioeconomic data, a neuropsychological evaluation, and a criteria checklist for diagnosis of dementia.

Relationship assessments were also collected at baseline and included questions on marital status, size of social network, satisfaction level, perceptions of being misunderstood, and level of reciprocity in social exchanges.

In addition, all patients were "free of dementia at the time of enrollment and also at the next 2 follow-ups to minimize the problem of reverse causality," explain the researchers.

In other words, for this analysis, dementia case incidence was considered only for those diagnosed at the 5-year and later follow-ups.

Satisfaction, Reciprocity Reduce Risk

Results showed a total of 461 cases of dementia and 373 cases of AD diagnosed between the 5- and 15-year follow-up period.

The participants who said they were "very satisfied" with their social interactions had a significantly lower dementia risk than did those who reported feeling "poorly or not satisfied" with their relationships (relative risk [RR], 0.77; 95% confidence interval [CI], 0.6 – 0.9; P = .03).

In addition, those who reported receiving more from others than they gave also had a significantly lower risk of developing dementia than did the participants who reported receiving as much as they gave (RR, 0.46; 95% CI, 0.2 – 0.9; P = .03).

"There was no significant association between the other social network variables and the risk of subsequent dementia," report the study authors.

After adjusting for variables, those who reported receiving "more support than they gave" over their lifetime also had a 53% reduced risk of developing AD (P = .05).

No other significant associations were found between relationships and AD risk.

The overall results show that "rather than having a lot of social partners, what may be important is having been surrounded by people with whom one experienced a genuine exchange," write the study authors.

"Our next step will be to better understand the cognitive mechanisms that could explain such results," said Dr. Amieva.

In addition, the researchers report that "it would be interesting" to evaluate specific personality traits of people who report being satisfied with their relationship in future studies.

"It is hard to know whether they are individuals with some type of magnanimous personality that draws people to them or whether their attitude to life is one of such gratitude that they feel plenty satisfied with their relationships and unable to ever fully reciprocate the generosity that has been bestowed on them," the study authors write.

"Nonetheless, these findings may lead to the recommendation that professionals working with elderly adults should pay special attention to the quality and reciprocity of...social networks," they add. The results may also "encourage the design of preventive strategies against dementia" that attempt to improve quality of relationships.

Expanding the Research

"Overall, I thought this study was interesting and very well done," Lisa L. Barnes, PhD, associate professor of neurological sciences and behavioral sciences at the Rush Alzheimer Disease Center in Chicago, Illinois, told Medscape Medical News.

"It had several strengths including that it was a long-standing, population-based study with a long followup period — longer than what most studies have had that looked at the influence of social networks on risk of dementia," added Dr. Barnes, who was not involved in this trial.

She noted that "another nice thing" was the attempt by the researchers to avoid reverse causality or that "people who had reduced social networks had this because they were already experiencing mild disease.

"They didn't overcome it completely but they did a good job by excluding the people who may have gotten the disease early in their follow-up period," explained Dr. Barnes.

Concerns cited included that there was no correlation found for size of social relationships.

"I was surprised that they didn't seem to find an association for the structural characteristics of the networks, didn't see that how many people you have in your network was important. That's something that's been shown in several previous studies."

She also suggested there could be some mental or personality trait associated with having a positive perception of networks — and that could be related to a lower risk for AD.

"It seems that they did not have any data on personality factors so you can't really rule that out as an interpretation."

Overall, "this study is expanding the research showing that social networks may be important in risk of Alzheimer's disease in older adults," said Dr. Barnes. "Maybe it's more than just how big your network is; maybe it's also how you feel about the network. Are you satisfied and are you getting something out of it? This might be something that clinicians would want to ask their patients.

"I think the important thing for research in general, even beyond clinicians, is that this is another example of a potentially modifiable factor that's associated with reduced risk of dementia and Alzheimer's disease. So it has important implications for disease prevention.

"If this is true, then maybe we should get rid of all the negative networks that drain on us and instead surround ourselves with positive people," said Dr. Barnes.

This study was funded in part by Novartis Pharma (France), Ipsen, Agrica, and a grant from the CNSA. The study authors and Dr. Barnes have disclosed no relevant financial relationships.

Psychosom Med. Published online August 31, 2010.

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