Featured Research

from universities, journals, and other organizations

Depression Is A Risk Factor Rather Than Early Sign Of Alzheimer's Disease, Study Suggests

Date:
April 10, 2008
Source:
Rush University Medical Center
Summary:
A new study supports the idea that depression is truly a risk factor for Alzheimer's disease rather than a subtle early sign of its underlying pathology. The study found no evidence of an increase in depressive symptoms during the prodromal phase before the clinical diagnosis of Alzheimer's disease.

A new study by researchers at Rush University Medical Center supports the idea that depression is truly a risk factor for Alzheimer's disease rather than a subtle early sign of its underlying pathology. The study found no evidence of an increase in depressive symptoms during the prodromal phase before the clinical diagnosis of Alzheimer's disease.

Numerous observational studies have found higher levels of depressive symptoms in old age to be associated with increased incidence of Alzheimer's disease and mild cognitive impairment. However, previous studies have not been able to answer the question of whether depressive symptoms actually contribute to the development of dementia (risk factor hypothesis) or are a consequence of the disease (reverse causality hypothesis.)

Robert S. Wilson, PhD, a neuropsychologist at the Rush Alzheimer's Disease Center, and colleagues examined data from the Rush Religious Orders Study, a cohort of 917 older Catholic clergy without dementia at study onset, to examine the change in depressive symptoms of Alzheimer's disease before and after the emergence of the cognitive symptoms of the disease.

For up to 13 years, the study participants underwent annual clinical evaluations that included assessment of depressive symptoms, cognitive testing, and clinical classification of mild cognitive impairment (MCI) and Alzheimer's disease. During the study period, 190 participants developed Alzheimer's disease.

Consistent with earlier findings in the Rush Religious Orders Study, having more depressive symptoms at baseline was associated with increased incidence of Alzheimer's disease and MCI.

However, the study found that those who developed Alzheimer's disease showed no increase in depressive symptoms before clinical diagnosis. Researchers were able to observe patients during a mean of approximately four years before the onset of dementia. Additionally, researchers saw no increase in depression during the three to four years preceding the onset of MCI, which antedates the onset of dementia by several years.

"If depressive symptoms are a consequence of dementia or a reaction to declining function, depressive symptoms would likely increase at some point before dementia is clinically evident," said Wilson. "We observed no such increase."

The study also found that even after the diagnosis of Alzheimer's disease was made there was no general increase in depression, but rather an increase that was confined to individuals with certain personality traits.

"Depressive symptoms may be associated with distinctive changes in the brain that somehow reduce neural reserve, which is the brain's ability to tolerate the pathology associated with Alzheimer's disease," said Wilson. "Understanding how depression contributes to the development of Alzheimer's disease may suggest new approaches to disease prevention."

Journal reference: Arch Gen Psychiatry. 2008;65[4]:439-446.

The research was supported by grants from the National Institutes on Aging, which leads the Federal effort to support and conduct basic, clinical, and social and behavioral studies on aging and on Alzheimer's disease. The Rush Alzheimer's Disease Center is one of 29 NIA-supported Alzheimer's Disease Centers across the United States.


Story Source:

The above story is based on materials provided by Rush University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Rush University Medical Center. "Depression Is A Risk Factor Rather Than Early Sign Of Alzheimer's Disease, Study Suggests." ScienceDaily. ScienceDaily, 10 April 2008. <www.sciencedaily.com/releases/2008/04/080407160731.htm>.
Rush University Medical Center. (2008, April 10). Depression Is A Risk Factor Rather Than Early Sign Of Alzheimer's Disease, Study Suggests. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2008/04/080407160731.htm
Rush University Medical Center. "Depression Is A Risk Factor Rather Than Early Sign Of Alzheimer's Disease, Study Suggests." ScienceDaily. www.sciencedaily.com/releases/2008/04/080407160731.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins