Depression is commonly reported in people with Alzheimer's disease and its precursor, mild cognitive impairment, with several studies suggesting having a history of major depression may nearly double your risk of developing dementia later in life. However, it has been unclear if depression is a symptom of the disease or a potential cause of the disease.
To study the relationship between Alzheimer's and depression, researchers at Rush University Medical Center tracked symptoms of depression during the transition from no cognitive impairment to dementia and found that depressive symptoms show little change during the development and progression of Alzheimer's disease. The study will be published in the July 6 issue of Neurology, the medical journal of the American Academy of Neurology.
"Our study suggests that depression is truly a risk factor for Alzheimer's disease," said lead author Robert S. Wilson, PhD, senior neuropsychologist, Rush Alzheimer's Disease Center, and a professor in the Department of Behavioral Sciences at Rush. "If depression was an early sign of the disease, we would expect to see it increase prior to diagnosis and as the disease progresses. Our study found very little change."
"Depression should not be viewed as an inevitable part of Alzheimer's disease. If a patient with Alzheimer's has depression, the depression should be treated," said Wilson.
The study involved participants in the Chicago Health and Aging Project, a longitudinal study of risk factors for Alzheimer's disease involving a population of older adults on Chicago's south side. At three year intervals, the entire population completed a brief self-report measure of depressive symptoms and clinical evaluations for Alzheimer's disease.
Initial analyses focused on a group of 357 individuals who developed Alzheimer's disease during the course of the study. The study found a barely perceptible increase in depressive symptoms, a rate of 0.04 symptoms per year, during six to seven years of observation before the diagnosis of Alzheimer's disease and no change during two to three years of observation after the diagnosis.
Because dementia may reduce the accuracy of self-report, in a subgroup of 340 participants, researchers conducted additional analyses of change in depressive symptoms by interviewing family, friends and other who were close to the study participants. Neither Alzheimer's disease nor its precursor, mild cognitive impairment, was associated with change in depressive symptoms during a mean of three years of observation.
The results were consistent across all demographics. There was no evidence that sex, age, education or race modified the trajectory of depressive symptoms before or after Alzheimer's disease was diagnosed.
"Here is this terrible disease that robs people of who they are and their ability to function and yet it doesn't make them depressed," said Wilson. "Alzheimer's may disrupt the ability to have prolonged bouts of negative emotions, in much the same way it disrupts many other activities."
The study authors suggest additional studies of patients with Alzheimer's disease for longer periods to determine if depressive symptoms may eventually decrease as the disease becomes more severe.
In addition, researchers at Rush continue to look at why depression increases the risk of Alzheimer's disease.
The study was supported by funding from the National Institutes of Health (NIH)/ National Institute on Aging (NIA). Co-authors include G.M. Hoganson, BS; K.B. Rajan, PhD; L.L. Barnes, PhD; C.F. Mendes de Leon, PhD; and D.A. Evans, MD.
The Rush Alzheimer's Disease Center (RADC) is one of 29 Alzheimer's disease research centers across the country designated and funded by the National Institute on Aging. The center is dedicated to reducing disability due to Alzheimer's disease and other age-related conditions through research on the treatment and prevention of disease for this and future generations. Since 1985, the RADC has provided services to more than 5,000 Alzheimer's patients and their families through its outpatient clinic.
Rush is a not-for-profit health care, education and research enterprise comprising Rush University Medical Center, Rush University, Rush Oak Park Hospital and Rush Health. Rush University is home to one of the first medical colleges in the Midwest and one of the nation's top-ranked nursing colleges, as well as graduate programs in allied health, health systems management and biomedical research.
Kim Waterman | EurekAlert!
Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University
The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering