Featured Research

from universities, journals, and other organizations

Early Warning Signs Of Alzheimer's Show Up Across Cognitive Areas Years Before Official Diagnosis

Date:
August 1, 2005
Source:
American Psychological Association
Summary:
By combing through dozens of Alzheimer's disease (AD) studies, psychologists have gained a clear picture of cognitive problems in people who will develop the degenerative brain disease. The meta-analysis reveals that people can show early warning signs across several cognitive domains years before they are officially diagnosed, confirming that Alzheimer's causes general deterioration and tends to follow a stable preclinical stage with a sharp drop in function.

Washington - By combing through dozens of Alzheimer's disease (AD) studies, psychologists have gained a clear picture of cognitive problems in people who will develop the degenerative brain disease. The meta-analysis reveals that people can show early warning signs across several cognitive domains years before they are officially diagnosed, confirming that Alzheimer's causes general deterioration and tends to follow a stable preclinical stage with a sharp drop in function. The findings appear in the July issue of Neuropsychology, which is published by the American Psychological Association.

Related Articles


Researchers at the Karolinska Institute and Stockholm Gerontology Research Center, affiliated also with the Max Planck Institute for Human Development and the University of South Florida, crunched the data from a decade's worth of studies: Published reports that met stringent criteria had records on 1,207 people with preclinical Alzheimer's (they later developed the disease) and 9,097 controls who stayed healthy.

Neuropsychologists are striving to understand the preclinical stage for two reasons: On the theoretical level, understanding the transition from normal aging to dementia is vital to understanding how the disease evolves. On the clinical level, treatment can work best when doctors can identify at-risk individuals as early as possible.

The authors studied 47 peer-reviewed studies published between January 1985 and February 2003. The year 1985 marked the introduction of more systematic and reliable diagnostic criteria for Alzheimer's.

The analysis showed that no matter what kind of study, people at the preclinical stage showed marked preclinical deficits in global cognitive ability, episodic memory, perceptual speed, and executive functioning; along with somewhat smaller deficits in verbal ability, visuospatial skill, and attention. There was no preclinical impairment in primary memory.

The generalized nature of the problem is consistent, say the authors, with recent observations that multiple brain structures and functions are affected long before the AD diagnosis. They remind readers that the deficits seen in preclinical AD mirror quite closely those seen in normal aging, such as impairments in episodic memory, executive functioning, and cognitive speed. Still, says lead author Lars Bäckman, PhD, these problems are exacerbated in those who will go on to be diagnosed with dementia.

He explains, "There are no clear qualitative differences in patterns of cognitive impairment between the normal old 75-year old and the preclinical AD counterpart. Rather, we think of the normal elderly person, the preclinical AD person, and the early clinical AD patient as representing three instances on a continuum of cognitive capabilities. This presents an obvious challenge for accurate early diagnosis."

The data also supported the emerging consensus that AD's preclinical period is characterized by an early onset followed by relative stability until a few years before diagnosis, when functioning plummets.

Bäckman and his colleagues endorse a multi-variable approach to understanding the preclinical stage of AD because this approach will help clinicians to more accurately predict the likelihood of disease.

The study traced other interesting patterns. People younger than 75 years at baseline were more impaired at the outset than people older than 75 at baseline. Impairment was also greater for the patients with shorter periods (fewer than three years) to diagnosis. These findings suggest that preclinical impairment is greater when the disease starts younger and progresses more quickly, due to more widespread and severe brain lesions among younger cases.

Article: "Cognitive impairment in preclinical Alzheimer's disease: A meta-analysis;" Lars Bäckman, PhD, Karolinska Institute, Stockholm Gerontology Research Center and Max Planck Institute for Human Development; Sari Jones, PhD, Anna-Karin Berger, PhD, and Erika Jonsson Laukka. PhD, Karolinska Institute and Stockholm Gerontology Research Center; Brent J. Small, PhD, University of South Florida. Neuropsychology, Vol. 19, No. 4.


Story Source:

The above story is based on materials provided by American Psychological Association. Note: Materials may be edited for content and length.


Cite This Page:

American Psychological Association. "Early Warning Signs Of Alzheimer's Show Up Across Cognitive Areas Years Before Official Diagnosis." ScienceDaily. ScienceDaily, 1 August 2005. <www.sciencedaily.com/releases/2005/07/050731231638.htm>.
American Psychological Association. (2005, August 1). Early Warning Signs Of Alzheimer's Show Up Across Cognitive Areas Years Before Official Diagnosis. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2005/07/050731231638.htm
American Psychological Association. "Early Warning Signs Of Alzheimer's Show Up Across Cognitive Areas Years Before Official Diagnosis." ScienceDaily. www.sciencedaily.com/releases/2005/07/050731231638.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) — Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
Yoga Could Be As Beneficial For The Heart As Walking, Biking

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Newsy (Dec. 17, 2014) — Yoga can help your weight, blood pressure, cholesterol and heart just as much as biking and walking does, a new study suggests. Video provided by Newsy
Powered by NewsLook.com
1st Responders Trained for Autism Sensitivity

1st Responders Trained for Autism Sensitivity

AP (Dec. 16, 2014) — More departments are ordering their first responders to sit in on training sessions that focus on how to more effectively interact with those with autism spectrum disorder (Dec. 16) Video provided by AP
Powered by NewsLook.com
Guys Are Idiots, According To Sarcastic Study

Guys Are Idiots, According To Sarcastic Study

Newsy (Dec. 12, 2014) — A study out of Britain suggest men are more idiotic than women based on the rate of accidental deaths and other factors. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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