We still don't know whether symptoms like irritability and sadness are due to people realizing they are having problems with memory and thinking, or whether these symptoms are caused directly by Alzheimer's effects on the brain.
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The information obtained in this study is interesting and important. This is particularly important for baby boomers, their children, and families.
I think most caregivers would tell you that the four points made below would apply all or in part to their loved one.
Early diagnosis of Alzheimer's is imperative if you want to have the best of all possible outcomes. This information should be shared widely across social media.
- Those who developed dementia during the study were more likely to have mood and behavioral changes first.
- For example, four years into the study, 30 percent of those who would go on to develop dementia had developed depression.
- In comparison, after the same period of time, only 15 percent of those who did not develop dementia during the study had become depressed.
- In addition, those who would go on to develop dementia were more than 12 times as likely to have delusions than those who did not develop dementia.
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Depression and behavioral changes may occur before memory declines in people who will go on to develop Alzheimer's disease, according to new research at Washington University School of Medicine in St. Louis.
Researchers have known that many people with Alzheimer's experience depression, irritability, apathy and appetite loss but had not recognized how early these symptoms appear.
Pinpointing the origins of these symptoms could be important to fully understanding Alzheimer's effects on the brain and finding ways to counteract them.
"There has been conflicting evidence on the relationship between Alzheimer's and depression," said senior author Catherine M. Roe, PhD, assistant professor of neurology. "We still don't know whether some of these symptoms, such as irritability and sadness, are due to people realizing on some level that they are having problems with memory and thinking, or whether these symptoms are caused directly by Alzheimer's effects on the brain."The study appears Jan. 14 in Neurology.
Roe and her colleagues at the university's Charles F. and Joanne Knight Alzheimer's Disease Research Center analyzed data on 2,416 people ages 50 and older. Scientists regularly evaluated the participants for up to seven years, including how they performed in extensive tests of mental function and psychological health.
All of the participants were cognitively normal at the start, but over the course of the study, 1,218 of them developed dementia.
Those who developed dementia during the study were more likely to have mood and behavioral changes first. For example, four years into the study, 30 percent of those who would go on to develop dementia had developed depression. In comparison, after the same period of time, only 15 percent of those who did not develop dementia during the study had become depressed. In addition, those who would go on to develop dementia were more than 12 times as likely to have delusions than those who did not develop dementia.
Alzheimer's researchers have been working to develop markers they can use to diagnose disease before the onset of dementia. The hope is to begin treating the condition before patients develop dementia.
However, Roe cautioned that the mood changes will not work well as markers in this regard until researchers better understand how these changes are connected to the disease.
Washington University School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report.
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The research was funded by the Longer Life Foundation; the National Institute on Aging of the National Institutes of Health (NIH), grants P50 AG005681, P01 AG003991, P01 AG026276, U01 AG016976; Fred Simmons and Olga Mohan; the Farrell Family Research Fund; and the Charles and Joanne Knight Alzheimer's Research Initiative of the Washington University Knight Alzheimer's Disease Research Center.
Objectives: To observe the natural time course of noncognitive symptoms before the onset of symptomatic Alzheimer disease dementia.
Methods: Using the National Alzheimer's Coordinating Center Uniform Data Set from September 2005 to March 2013, data from cognitively normal individuals who were aged 50 years or older at first visit and had subsequent follow-up were analyzed. Survival analyses were used to examine the development of particular symptoms relative to each other on the Neuropsychiatric Inventory Questionnaire (NPI-Q), Functional Activities Questionnaire, and Geriatric Depression Scale, and to compare the development of individual symptoms for persons who did and did not receive a Clinical Dementia Rating (CDR) >0 (indicating abnormal cognition) during the follow-up period.
Results: The order of symptom occurrence on the NPI-Q was similar for participants who remained at CDR 0 and for those who received a CDR >0 over the follow-up period, although the time to most NPI-Q symptoms was faster for participants who received a CDR >0 (p < 0.001). With the exception of memory, Geriatric Depression Scale symptoms reported by both CDR groups were similar.
Conclusions: We found a significantly earlier presence of positive symptoms on the NPI-Q in cognitively normal patients who subsequently developed CDR >0. Among participants with no depression symptoms at baseline, results suggest that depressive symptoms may increase with aging regardless of incipient dementia. Such findings begin to delineate the noncognitive course of Alzheimer disease dementia in the preclinical stages. Future research must further elucidate the correlation between noncognitive changes and distinct dementia subtypes.
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