DOES CARING FOR A PARTNER WITH DEMENTIA INCREASE YOUR OWN RISK?
Posted May 08 2010 2:31pm
In Britain there are seven hundred & fifty thousand people with dementia, & it is predicted that this will rise to 1.7 million by 2050. Now a new study - published in the Journal of the American Geriatrics Society - shows that caring for a partner with dementia is associated with a six fold increase in the risk of developing the condition compared to those whose partner was dementia free.
The study followed one thousand two hundred & twenty one couples over a period of twelve years. All were at least sixty five years of age at the start. Tests to assess memory & reasoning were regularly administered in order to identify any impact on the care giver. Where the results suggested the presence of dementia, participants were seen by a specialist to confirm the diagnosis.
The onset of the condition was defined as the age when the subject met the criteria for dementia as defined by the Diagnostic and Statistical Manual of Mental Disorders. By the end of the study two hundred & fifty five of the participants had developed dementia, indicating that having a partner with dementia resulted in a six fold increased risk of developing the condition. Interestingly the risk for men was substantially higher: increase was almost twelve fold, as compared to a four-fold increase for women.
The team of researchers, astounded by the initial results, analysed the data again taking account of factors such as socio-economic status which might indicate shared environmental risks, & whether participants had a form of the APOE gene that raises the risk for Alzheimer’s disease. There was no significant change in the results.
The study doesn’t explain the reason for the increased risk. The researchers suggest two major possibilities which are not mutually exclusive. One is that the distress, grief, and difficulty involved in caring for a partner with dementia may directly increase the risk of getting dementia. It is entirely feasible that stress, lack of sleep & exhaustion can contribute to memory loss. The second is to do with shared lifestyle & environmental risks. However, the study factored in some of these, & the researchers felt it unlikely they would account for all the increased risk.
Dr. Gary Small, an expert in the field who had no connection with the research made reference to previous research findings which might shed light on the results, “Studies have shown that caregivers for dementia patients have a high risk for major clinical depression. And there has been a study that showed that people who are prone to stress are at higher risk for Alzheimer’s.”
Other research has shown that stress can damage a part of the brain that is involved with memory. “Studies have shown that lab animals under stress have fewer cells in the hippocampus,” Small said. “And when human volunteers are injected with the stress hormone cortisol, they end up with a temporary impairment of memory.” Shrinkage of the hippocampus has been shown to occur in dementia.
Small also postulated on why male care givers were at greater risk, “That finding is consistent with the sex specific roles that people still tend to take on in marriage,” he explained.
Dr Maria Norton – the lead researcher of the study & an associate professor in the department of Family, Consumer and Human Development at Utah State University, in Logan. - said: “Future studies are needed to determine how much of this association is due to caregiver stress compared to a shared environment.
“It’s possible that we’ll find that there is something that the caregivers who developed dementia had in common, such as a particular personality trait or their coping styles. Or, maybe it isn’t as much about the caregiver so much as it is about the spouse who gets dementia first: how rapidly they decline, whether they have delusions. Not all dementias are the same. Some might be more stressful to the caregiver.”
“On the positive side, the majority of these individuals, with spouses who develop dementia, did not themselves develop dementia, therefore more research is needed to explore which factors distinguish those who are more vulnerable.”
Regardless of the reasons for the findings, they highlight the importance of taking care of the carer. Dr Norton said that the results alerted us to the increased risk for some care givers, “We need to be taking care of the caregiver and finding ways to maximize the positives of care giving.”
On the issue of dementia she concluded, “Given the significant public health concern of Alzheimer’s disease and other dementias, and the forthcoming shift in population age composition, continued research into the causes of dementia is urgent.”