Close caregiver relationship may slow Alzheimer's decline

Study believed first to document potential impact of emotional closeness on course of disease

23 july 2009--A study led by Johns Hopkins and Utah State University researchers suggests that a particularly close relationship with caregivers may give people with Alzheimer's disease a marked edge over those without one in retaining mind and brain function over time. The beneficial effect of emotional intimacy that the researchers saw among participants was on par with some drugs used to treat the disease.

A report on the study, believed to be the first to show that the patient-caregiver relationship may directly influence progression of Alzheimer's disease, is published in the September 2009 The Journals of Gerontology Series B: Psychological Sciences and Social Sciences and currently available online.

"We've shown that the benefits of having a close caregiver, especially a spouse, may mean the difference between someone with AD staying at home or going to a nursing facility," says Constantine Lyketsos, M.D., M.H.S., the Elizabeth Plank Althouse Professor in Alzheimer's Disease Research and director of the Johns Hopkins Memory and Alzheimer's Treatment Center.

Lyketsos cautions that it remains unclear how or why this benefit was evident in the study, since the results may be due to milder forms of Alzheimer's disease among those who reported close relationships. "A close relationship might prompt caregivers to deliver more attentive treatment, but it might be the other way around, with a milder illness helping caregivers stay close," Lyketsos says. "Our next study is designed to detangle what's going on."

Researchers have long been interested in the relationships between caregivers and Alzheimer's disease patients, with many studies focusing on the well-being of caregivers. However, little was known about the converse relationship—how caregivers affect the well-being of people with Alzheimer's disease.

To find out, Lyketsos and colleagues at Johns Hopkins, Utah State, University of Washington, Duke University and Boston University examined 167 pairs of caregivers and Alzheimer's patients. The pairs were recruited from the Cache County (Utah) Dementia Progression Study, which has tracked hundreds of people with Alzheimer's and other types of dementia since 1994. All of the study participants live in Cache County, whose residents topped the longevity scale in the 1990 United States census.

Starting in 2002, the researchers met with patient-caregiver pairs in their homes every six months for periods up to four years. At each meeting, the patients underwent a battery of tests to assess physical, cognitive, functional and behavioral health. The researchers also interviewed the caregivers — spouses, adult children or adult children-in-law — about the caregiving environment and gave them a survey to assess how close their relationships were with the patients. The survey asked caregivers to rate their level of agreement or disagreement with six statements, such as "My relationship with the care recipient is close"; "The care recipient makes me feel like a special person"; and "The care recipient and I can always discuss things together."

At the outset of the study, all patients scored similarly on cognitive and functional tests. However, as time progressed, the researchers found marked differences between patients whose caregivers had scored their relationships as close or more distant on the surveys. Patients with whose caregivers felt particularly close to them retained more of their cognitive function over the course of the study, losing less than half as many points on average by the end of the study on a common cognitive test called the Mini-Mental State Exam (MMSE), compared to patients with more distant caregivers. Patients with close caregivers also scored better on a functional test called the Clinical Dementia Rating, remaining significantly closer to baseline over time compared to those with more distant caregivers.

The "closeness effect" was heightened for pairs in which the caregiver was a spouse, as opposed to an adult child or in-law. Patients with close spouses declined the slowest overall, with scores on the MMSE showing changes over time similar to patients participating in recent clinical trials for FDA-approved Alzheimer's drugs called acetylcholinesterase inhibitors.

"We've shown that the benefits of having a close caregiver, especially a spouse, may be substantial. The difference in cognitive and functional decline over time between close and not-as-close pairs can mean the difference between staying at home or going to a nursing facility," says Lyketsos.

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The study was funded by grants from the National Institute on Aging, one of the National Institutes of Health.