Scientists Seek Sense of Balance

President John F. Kennedy's famous White House secretary Evelyn Lincoln described her key to maintaining intellectual vitality 21 years ago: "It's not who you are, but who you associate with that's important in life," she told a Detroit Free Press reporter.1 Although Lincoln was describing a philosophy of deep involvement with family, learning, and career--a career that kept her life enriched through a series of fascinating relationships with power figures--her philosophy now is gaining new credence in scientific observations of the elderly. What, after all, keeps a human mind active and vital throughout life, even into the seventh, eighth, and ninth decades? One answer, researchers find, is a rich network of social interactions and commitments. These include satisfying contact and "bi-directional" engagement in community, children, relatives, and friends--people helping people, communicating effectively and participating in complex interpersonal exchanges. Recent research in Sweden and the United States suggests that strong social networks may actually help protect the elderly from cognitive decline, dementias, and other psychological problems, including depression. Engagement in social activities not only provides a sense of purpose and cognitive stimulation, but it may actually delay the onset of dementias and lower the risk of Alzheimer's disease.2 Consequently, a new emphasis on social structures and interventions --rather than purely biological or genomic explanations of dementias--could be taking center stage as studies of the elderly progress. Until recently, geriatric research has focused on the effects of social networks on general health issues and mortality and morbidity, according to Laura Fratiglioni, a neurologist and professor of medical epidemiology at the Karolinska Institutet in Stockholm, Sweden. But when Fratiglioni published her landmark paper last April,3 based on interview data derived from the famous Kungsholmen Project in Stockholm (named after a central district where study participants lived), cognition research took a dramatic turn. "We drew on our hypothesis that [absence of] a social network would be related to increased risk of dementias," she said. Fratiglioni, among a large group of scientific collaborators, followed 1,200 elderly study subjects over an average period of three years. "I've been following the group since 1989 [the study actually began in 1987]," she said. "Originally there were 1,800, but 1,203 were chosen for the cognition study because they had good cognition at the start of the research. "We had found that old women over the age of 80 have the highest risk of dementia--more than men--and I was trying to explain why. Other European studies had done analysis according to other factors--cognition and dementias related to education, for example, or cardiovascular risk," Fratiglioni continues. "But in discussing the differences, we found that what makes old women different from old men is that they tend to live alone more; they survive more than their men; and the men are often married to a younger wife, so men have more company in general. We started to think about social isolation. Therein engendered a study specifically focused on how the structural and qualitative features of social networks--including marital status, living arrangement, having children, and forming satisfying ties with children, friends and relatives--affected the development of dementias in the healthy elderly." Laura Fratiglioni Living vs. Being Alone The results were definitive. Fratiglioni and colleagues found that living alone was less significant or risky than being alone. In short, those with strong social networks had less risk of developing dementias than those with very limited social networks. Living alone did pose some increased risk for developing dementias over living with partners, married or not. But more significantly, the researchers found that satisfying relationships with social contacts--among them, children, friends and relatives--were more important than frequency of contact. Further, the study found that the risks for cognitive decline are higher among those having unsatisfactory contact with children than among those having no children at all. Fratiglioni's conclusion: Deeply satisfying contacts seem to protect against dementia, the most common mental disorder in the elderly. "When all components were combined in an index, a poor or limited social network increased the risk of dementia by 60 percent," she reported. Further, the study found a significant gradient of risk for the four degrees of social connection Fratiglioni had identified--the stronger the social connections and level of satisfaction, the more protective the effect. "This is an incredible new area of research," observed Lisa F. Berkman, chair of the department of health and social behavior, Harvard School of Public Health, who wrote a commentary on Fratiglioni's paper in the same issue of The Lancet.4 "Altogether there are probably no more than three or four papers on this exact topic--understanding how social conditions pattern our cognitive ability and our risk of decline, including the risk of Alzheimer's and dementias," she said. But the work is important "because people have started to wonder what are the mechanisms [tying] mental and physical outcomes to social isolation," Berkman said. Among others, Berkman did early research on the effects of social networks on mortality at the time the Swedish cohort studies were being done. "We looked at people who were socially isolated over a period of time and now people are wondering whether the [mechanisms] that contribute to causes of death also work for disabilities," she continued. "Now we have intriguing evidence on cognitive function and Alzheimer's, but it's a brand new area. For example, we know that degree of education predicts cognitive decline, ... but it's more about social engagement and being embedded in social networks [in an active way]," she said. To Berkman and Fratiglioni, social engagement mobilizes cognitive capacity; it stimulates and sets in place a 'use it or lose it' phenomenon that could be vital to successful aging. "Social environment is important for psychological balance in the elderly," Fratiglioni writes, citing French research showing a lower incidence of dementia in individuals who participate in more leisure, social, and work activities.5 "Social engagement promotes a commitment to community and family [and] provides a sense of purpose and fulfillment that rests on the bidirectionality of commitments," adds Berkman. "The mutuality of commitment moves beyond the unidirectional provision of emotional and instrumental support provided to the older person, which may even, in the extreme, inhibit functioningaccompanying story: Can Social interventions work. Thus, the power of engagement and the deep sense of affiliation and worthiness it provides may be the critical pathway through which social networks influence the onset of dementias or cognitive decline. Being alone is what is risky, not living alone."3 Up for Debate Berkman and Fratiglioni's observations are likely to be challenged, if not corroborated, in the near future. For example, Richard Suzman, associate director for behavior and social science research at the National Institute on Aging, cautions that there is a "chicken and egg" problem inherent in finding cause and effect between social relationships and cognition. "There's a question as to whether a decline in cognition precedes a decline in social interaction [in the elderly] or the other way around," he said. "It's quite possible that early preclinical signs of dementia may be noticed by friends, but not picked up in a clinical assessment." He believes early signs of decline "can lead to a loss of social relationships and interactions rather than the other way around. Or both may be operating in a spiral or interactively." Berkman's graduate student, Shari S. Bassuk, published a study in 1998 examining social engagement and cognitive decline in a community of more than 2800 noninstitutionalized elderly,5 finding, like Fratiglioni, a connection between rich social ties and cognitive health.6 In the 12-year study period, she found that the elderly study subjects (65 and over) with no social ties were more likely to experience cognitive decline as compared to those with a robust social life (five or six regular social ties). Bassuk's indicators of social engagement included the presence of a spouse, monthly visual contact with at least three relatives or close friends, and yearly nonvisual contact (telephone calls or letters) with at least 10 relatives or close friends, as well as frequent attendance at religious services or other groups, and regular participation in recreational social activities. Her conclusion? "Social disengagement is a risk factor for cognitive impairment among elderly persons," Bassuk writes. Teresa Seeman, a professor of medicine and epidemiology at University of California, Los Angeles, Medical School, has analyzed data on social relationships and cognition from the 1988-95 MacArthur Study on Successful Aging,7a cohort study of older adults selected to be 'high functioning' in Boston, New Haven, Conn., and Durham, N.C. Measuring cognition over a seven-year period in a cohort of 1,200 men and women ages 17-79, "our study did not find that the number of social relationships affected cognitive decline; rather, it was the quality [of social relationships]," Seeman said. The study, as yet unpublished, differs from Berkman and Fratiglioni's findings because "in our cohort, few of our high functioning people were socially isolated. Most had a lot of social interaction with spouse, close friends, and other relationships." Thus, social isolation didn't predict cognitive decline; rather, the essence of cognitive health lay in the "quality of those relationships, specifically the amount of support you received; the people who received more support were less likely to decline," Seeman said. She believes that only in the last decade have researchers developed adequate measures to test cognition of the elderly in population-based research. Conflicts and Complications With or without these measures, though, some researchers are reluctant to draw the same general conclusions as Fratiglioni. At the Gerontology Research Centre in Lund, Sweden, for example, associate professor Gillis Samuelsson has not found direct relationships between quality or quantity of social interactions and onset of dementias. "We have several factors or variables, including education, demographics, social class, and economic status, but not one of these has had predictive value for patients being demented" (including all classes of dementias, not just Alzheimer's), he said. "When we evaluate our data looking forward 25 years, we see social networks changing, and it's complicated. For example, we've looked at loneliness and the relationship to dementia and other mental disorders and there are no correlations of risk in either direction [referring to data he has collected on 192 pensioners from 1969 onward]. On the other hand, we identified that one risk factor for having dementia was living in rural areas; we've also seen the risk increasing for women." Cause and effect relationships can be confounding. For example, Samuelsson's studies indicated that smokers are less likely to experience development of dementias than nonsmokers, an observation that may have to do with mortality and morbidity increases for smokers earlier in life, he suggests. Further, he believes that many other psychological problems--depression and anxiety, for example--have been largely ignored in geriatric evaluations. "Dementia has been the focus for many years now because it's a very hard problem in terms of caring and support," he said. "But other mental disorders such as depression and anxiety are problems, too. We've forgotten in some ways that these mental problems can be just as debilitating as [the dementias] are." In the United States, research on social interactions and cognitive decline have largely taken a back seat to other geriatric programs. The NIA, however, is now conducting a large-scale project (named ACTIVE) to evaluate behavioral interventions to improve cognitive performance as people age. Preliminary results of that study will not be available for another year. "There's a lot of work on cognitive aging, but most has been focused on the events and processes that happen rather than on the ways in which social relationships may influence the rate of cognitive decline," said Daniel Berch, secial expert at the NIA. North American research emphasis has been focused principally on mortality and morbidity issues-the broader based aspects of decline. But Berch and Suzman were sufficiently impressed with Fratiglioni's work that she was invited to speak at an NIA workshop held in Washington, D.C. in December 2000-a workshop that Berch said was very well received. "More than a decade ago, it was demonstrated that social isolation is as important a risk factor for predicting general morbidity and mortality in the elderly as high blood pressure and smoking," he said. To make the final leap-inferring relationships between cognition and the quality, structures, and components of social interaction, living arrangements, emotional attachments, and other factors-represents a "next phase" advancement based on more sophisticated tools, he adds. Reorganizing at the NIA "It's only been recently that people have been working in these domains and thinking about the impact of social relationships," he said. "People who are studying dementia and cognitive decline have reached the point in their work where they're looking at precursors of dementia, such as mild cognitive impairments-what some believe are the early signs of Alzheimer's," he said. At NIH, there has been a bias toward genomics and studying the genetic/biological basis for dementias. "Support for biological research is heavier than behavioral, but that's beginning to change," Berch adds. "Professional associations representing social and behavioral scientists are increasingly advocating for more funding of behavioral research-it's crucial." There is more support, and a slowly gathering recognition of the impact of such areas as 'social neuroscience'-understanding how social factors influence brain development and function. The NIA has recently reorganized its behavior research program into a psychological development and integrative sciences unit that will encourage studies combining diverse levels of sociocultural, psychological, biological and genetic analysis on behavioral and functional aging. The National Academy of Sciences has published a report: Cells & Survey: Should Biological Measures Be Included in Social Science Research? And last year, the NIA fronted a NAS panel to look at integrating the field more.8 Suzman believes that Fratiglioni's work is a compelling catalyst for very large studies identifying the quality and density of social networks and interventions on elderly cognitive health. Arielle Emmett (arielleem@snip.net) is a contributing editor for The Scientist. References 1. A. Emmett, "Two who chose the Kennedys," Detroit Free Press, Dec. 14, 1978. 2. K. Kondo, I. Yamashita, A case-control study of Alzheimer's disease in Japan: association with inactive psychosocial behaviors. In: Hasegawa K. Homma A., eds., Psychogeriatrics: biochemical and social advances. Amsterdam: Excerpta Medica, 1990: 49-53. 3. L. Fratiglioni, "Influence of social network on occurrence of dementia: a community-based longitudinal study,'' Lancet, 355:1315-9, 2000. 4. L.F. Berkman, "Which influences cognitive function: Living alone or being alone?" Commentary, Lancet, 355:1291-2, 2000. 5. C. Fabrigoule et al., "Social and leisure activities and risk of dementia: a prospective longitudinal study." Journal of the American Geriatric Society, 43:485-90, 1995. 6. S.S. Bassuk, "Social disengagement and incident cognitive decline in community-dwelling elderly persons," Annals of Internal Medicine, 1312:165-73, 1999. 7. L.F. Berkman et al., "High, usual and impaired functioning in community-dwelling older men and women--findings from the MacArthur Foundation research network on successful aging," Journal of Clinical Epidemiology, 46:1129-40, 1993.

Scientists Seek Sense of Balance

Feb 4, 2001

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