LOGAN -- Now there's something else to worry about: A Utah State University associate professor's research strengthens the link between long-term stress and dementia.
The research, led by Maria Norton, of USU's Department of Family, Consumer and Human Development, is based on data from the recently completed 15-year Cache County Memory Study.
Norton's hypothesis was that chronic stress can expose an individual to long-term levels of stress-related hormones, which results in chronically high levels of glucocorticoids, a natural chemical shown in both animal and human studies to increase the rate of neuronal cell death with long-term exposure.
The link has been made before, but Norton's new research links the increased rate of dementia specifically to people who:
* Lost a parent during their youth, or
* As an adult, served as caregiver to a spouse who suffers from dementia.
"We studied early parental death, which exposes children to high levels of stress early in their development and can compound over time," Norton said.
"If you have clinically high levels of stress due to a major stressor like parental death, those people might be more vulnerable.
"A person whose father died when they were an infant to age 4 has more than double the risk of Alzheimer's. People whose mother died while they were adolescents have more than double the risk of Alzheimer's."
If the surviving parent remarries, the stress effect seems to go away, she said, although it would take further studies to determine why.
Stress could be reduced by increased emotional support, more financial support, a more normal social standing or a healthier diet, among other possibilities, Norton said.
"At the other end of the spectrum, when a couple gets older and the husband or wife develops dementia, the other partner often becomes the caregiver," she said.
The study shows a woman who is the caregiver of a husband with dementia is three times more likely to develop dementia and that a man who is the caregiver for a wife with dementia is about 11 times more likely to develop dementia, Norton said.
The CCMS has provided 15 years of data on a pool of more than 5,000 participants from Cache County, Norton said. Ninety percent of people who were asked agreed to participate. Documentation included birth and death certificates, medical information and cognitive evaluations -- a pool of reliable data rarely found in the scientific world.
Norton found that some factors seemed to lower depression and stress, such as an individual's high levels of religious involvement, indicating that personal coping skills might reduce the risk of Alzheimer's.
"There are certainly some individuals who seem to weather stress and trials better than others, and as such, they don't tend to develop depression or face the long-term chronic exposure to the stress-related hormones that are linked to dementia," she said.
"This indicates that there may be preventive measures that can be taken to prevent or delay dementia. This study has helped us determine how to identify the more vulnerable subgroups of people who might benefit from stress management or other preventive interventions."
The "Lifespan Stressors and Alzheimer's Disease" study was funded by the National Institute on Aging. Findings from this study have been published in the Journal of the American Geriatrics Society, the Journals of Gerontology, and Age and Aging.