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What is Alzheimer’s disease?

Alzheimer’s disease is the most common type of dementia accounting for 60 to 80 percent of all diagnoses. [1]

It isn’t accurate to say that someone who has dementia also has Alzheimer’s or that all dementias are a form of Alzheimer’s.

As we know, Alzheimer’s disease is not a normal part of aging and unfortunately it is irreversible. It is a chronic neurodegenerative disease that destroys brain cells, causing thinking ability, memory, and language skills to deteriorate over time. A 2012 study commissioned by the Alzheimer’s Society of Canada, notes that 747,000 Canadians were living with cognitive impairment, which included, but was not limited to, dementia. In a 2010 report, the estimated prevalence of dementia alone was 500,000, based on previous studies in Canada and Europe. By contrast, based on administrative data from British Columbia, the estimated prevalence in Canada in 2011 was 340,000. It currently is the 8th leading cause of death in Canada[2]

Alzheimer’s disease is a devastating disease that causes changes in the brain that eventually affects all aspects of a person’s life – how they think, feel and act. The disease impacts everyone differently and while it’s difficult to predict symptoms, the order in which they appear or the speed of progression, there are warning signs people can watch out for.

Primary neurodegenerative disease, like Alzheimer’s disease, is clinically characterized by progressive memory loss, cognitive decline, mental and behavioural disorders, and progressive impairment of activities of daily living such as eating, bathing, toileting, dressing and basic self-maintenance.  

Severity of symptoms for Alzheimer’s disease is usually described in stages that have increasing level of impairments and assistance required. The stages begin with mild cognitive impairment (MCI), and move through mild, moderate and eventually end at the severe stage. In the MCI stage, patients show mild symptoms while maintaining awareness of their condition. They typically need minimal assistance, and the disease does not significantly impact their daily activities of life. 

In the mild to moderate stages, symptoms become more noticeable, and they begin to interfere with some or most of daily activities of life, and more assistance is needed to help the person finish their daily tasks.

Reaching the severe stage, language and communication ability is reduced and patients may be unable to communicate verbally or take care of themselves independently. Quality care is important to ensure the person has and adequate quality of life. At this stage, most patients are under assisted living care. 

As they near end of life, their cognitive decline has reached a point in which the person needs 24-hour care. The focus shifts to palliative care and providing comfort measures to ensure quality in end of life. The earlier the disease is diagnosed; it improves their chances for better quality of life.

Due to the devastating effects of Alzheimer’s disease and rising prevalence of cases due to the aging population, it is of importance to find new medications and treatments to treat Alzheimer’s disease. That’s why clinical research is a crucial step in finding cures and treatments for current diseases where the need is so great. 

For more information, contact the Medical Arts Health Research Group at or visit our website at

[1] Alzheimer’s Association. 2020 Alzheimer’s Disease Facts and Figures. Alzheimer’s Dement 2020;16(3):391+

[2] Alzheimer’s Society of Canada. Prevalence and Monetary Costs of Dementia in Canada. Pg.23.Table 2c.