Study finds cerebrovascular disease to be major determinant of psychosis in patients with Alzheimer's

January 5, 2016, St. Michael's Hospital
Diagram of the brain of a person with Alzheimer's Disease. Credit: Wikipedia/public domain.

About half of all patients with Alzheimer's disease develop symptoms of psychosis, such as delusions or hallucinations.

But the pathological mechanisms that underlie are unclear, limiting the ability to manage and treat them. Some studies have suggested they are related to the underlying causes of Alzheimer's disease such as the protein deposits found in the brains of Alzheimer's patients, but others found no correlation.

A study published today in the Journal of Alzheimer's Disease found that is a major determinant of psychosis in people with Alzheimer's disease. Cerebrovascular disease is a group of conditions that restrict the circulation of blood to the brain.

Using data from the National Alzheimer's Coordinating Centre database collected from 29 Alzheimer's disease centres in the United States between 2005 and 2012, researchers led by Dr. Corinne Fischer, a psychiatrist and researcher at St. Michael's Hospital, analyzed autopsy data from 1,073 people.

Of the 890 people who had been clinically diagnosed with Alzheimer's while they were alive, the people most likely to be psychotic were those whose autopsies showed they had more physical signs of Alzheimer's such as neuritic plaques (protein deposits) and neurofibrillary tangles (twisted fibers found inside brain cells).

But when they looked at the 728 people whose autopsies confirmed they had Alzheimer's, those with psychosis did not show increased physical evidence of Alzheimer's disease. Alzheimer's can only be confirmed through an autopsy, so some patients in the clinically diagnosed group had been misdiagnosed with Alzheimer's.

In both groups of patients, psychosis correlated significantly with Lewy bodies, abnormal protein aggregates found in nerve cells of patients with Parkinson's disease. This was not an unexpected finding since psychosis is prominent when dementia accompanies Parkinson's disease.

What was entirely unexpected was the prominent role in of (hypertension, diabetes, age at quitting smoking) and cerebral injuries related to small vessel disease,

About 19 per cent of people with Alzheimer's who live in the community (rather than in institutions) are thought to have delusions and 14 per cent have hallucinations. Psychotic symptoms are significant in Alzheimer's because they have been shown to be associated with increased burden on caregivers, increased functional decline and more rapid progression of the disease.

Explore further: Negative beliefs about aging predict Alzheimer's disease

Related Stories

Negative beliefs about aging predict Alzheimer's disease

December 7, 2015
Newly published research led by the Yale School of Public Health demonstrates that individuals who hold negative beliefs about aging are more likely to have brain changes associated with Alzheimer's disease.

Alzheimer's may affect the brain differently in African-Americans than European-Americans

July 15, 2015
Alzheimer's disease may cause different changes in the brain, or pathologies, in African-Americans than in white Americans of European descent, according to a study published in the July 15, 2015, online issue of the medical ...

Two Alzheimer's risk genes linked to brain atrophy, promise future blood markers

December 23, 2015
Two genetic variants previously linked to Alzheimer's disease have been more specifically tied to brain atrophy that is characteristic of the disease.

What is Lewy body dementia, which robbed robin williams of his sanity?

November 20, 2015
Oscar-winning actor and comedian Robin Williams died in August 2014 of suicide. His death was not due to substance abuse or suicidal tendencies, as some had speculated in the media. Williams' wife, Susan, told ABC's "Good ...

Antipsychotics increase risk of death in people with Parkinson's disease psychosis

September 30, 2015
Antipsychotic drugs may increase the risk of death in people with Parkinson's disease psychosis (PDP), according to a new study led by researchers from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's ...

Antipsychotics initiated frequently and used for long term in Alzheimer's patients

October 14, 2015
Antipsychotic drugs are initiated in patients with Alzheimer's disease (AD) more frequently than in the general population - already 2-3 years before the Alzheimer's diagnosis, according to a new study from the University ...

Recommended for you

Rocky start for Alzheimer's drug research in 2018

January 19, 2018
The year 2018, barely underway, has already dealt a series of disheartening blows to the quest for an Alzheimer's cure.

Alzheimer's disease: Neuronal loss very limited

January 17, 2018
Frequently encountered in the elderly, Alzheimer's is considered a neurodegenerative disease, which means that it is accompanied by a significant, progressive loss of neurons and their nerve endings, or synapses. A joint ...

Anxiety: An early indicator of Alzheimer's disease?

January 12, 2018
A new study suggests an association between elevated amyloid beta levels and the worsening of anxiety symptoms. The findings support the hypothesis that neuropsychiatric symptoms could represent the early manifestation of ...

One of the most promising drugs for Alzheimer's disease fails in clinical trials

January 11, 2018
To the roughly 400 clinical trials that have tested some experimental treatment for Alzheimer's disease and come up short, we can now add three more.

Different disease types associated with distinct amyloid-beta prion strains found in Alzheimer's patients

January 9, 2018
An international team of researchers has found different disease type associations with distinct amyloid-beta prion strains in the brains of dead Alzheimer's patients. In their paper published in Proceedings of the National ...

Advances in brain imaging settle debate over spread of key protein in Alzheimer's

January 5, 2018
Recent advances in brain imaging have enabled scientists to show for the first time that a key protein which causes nerve cell death spreads throughout the brain in Alzheimer's disease - and hence that blocking its spread ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.