What is Alzheimer’s disease?
Alzheimer's is the most common form of Dementia and is characterized by how it impacts a human's behavior, thinking, and most importantly, memory. The symptoms can worsen over time, and the individual may have difficulty carrying out daily activities. Memory lapses, or mild memory loss, are usually one of the first signs of Alzheimer's disease and symptoms continue to worsen over time, although the rate at which the disease progresses can vary.
Alzheimer's is a prevalent disease, with over 6 million Americans estimated to have Alzheimer's across all age groups in 2022, 73 percent of whom are 75 years or older. Although most studies have found no significant difference in the risk of developing Alzheimer's between men and women, almost two-thirds of Americans that have been diagnosed are women. Furthermore, studies have also shown that older Black Americans are twice more likely to develop Alzheimer's and other dementias, than older White Americans. It is expected that by the year 2050, 12.7 million people, 65 years or older may develop Alzheimer's.
Are dementia and Alzheimer’s the same thing?
Though Alzheimer’s and dementia are often used interchangeably, they are not exactly the same. Dementia is a general term for when an individual suffers a consistent decline in cognitive function often leading to difficulties in the ability to perform their day-to-day activities.
Several different conditions can cause dementia, and it can take many forms. Alzheimer’s, the most common form of dementia, accounts for 60-80% of dementia cases. Specifically, Alzheimer's is characterized by complex changes in the brain, which can lead to damage of healthy neurons in the brain, in turn causing the symptoms associated with Alzheimer's.
Subtypes of Dementia
There are multiple forms of Dementia. Here are the most common subtypes:
- Alzheimer's Disease
In this subtype, the person affected may have difficulty remembering where they are in time, and their short-term memory may be compromised. There are seven stages of Alzheimer's disease, which typically progress as the condition worsens over time.
- Lewy Body Dementia
Lewy Body dementia is the second most common subtype of the disease. Many experts describe it as a combination of Parkinson's and Alzheimer's. One of the most prominent symptoms of Lewy Body Dementia is visual hallucinations.
- Vascular Dementia
This type of Dementia is the result of damage to brain tissue caused by cardiovascular problems.
- Frontotemporal Dementia
Frontotemporal Dementia is caused by damage to the Frontal or Temporal lobes of the brain. Damage to these areas of the brain can affect the person’s ability to think, speak, and make decisions, leading to symptoms of this subtype.
Here are some of the early signs of Alzheimer’s that someone with early onset disease may exhibit:
- Memory loss (short-term)
- Impaired concentration, inability in problem-solving and planning
- The inability to complete daily life tasks
- Feeling out of place and time
- Unable to calculate the distance between spaces and forgetting items in different places
- Poor decision making
- Not being mentally present
- Mood changes or other personality/behavior changes
What are the stages of Alzheimer’s Disease?
Alzheimer’s disease is usually broken into four stages. Let’s take a closer look at these different stages and how they differ:
Alzheimer’s disease begins before any symptoms are visible. This is known as the preclinical stage, and can only be detected with special tests run in a laboratory. The preclinical stage of Alzheimer’s disease may last as long as decades - changes in the brain can be seen long before any behavioral changes are identified. As more advanced technology becomes available, it’s slowly becoming possible to detect Alzheimer’s disease in the preclinical stage. Researchers are currently working on ways to detect preclinical Alzheimer’s using a combination of brain imaging, biomarker tests, and cognitive tests.
Mild (early stage)
In the early stages of Alzheimer’s disease, a person may still be living a normal life. Driving, working, and participating in social activities are all still possible at this stage, but the individual may sometimes experience memory lapses. It often starts with small things, like forgetting familiar words, or where specific items in the home are located.
Moderate (middle stage)
In the moderate or middle stage of Alzheimer’s disease, the individual typically requires a deeper level of care. This is the longest stage of Alzheimer’s disease, and can often last many years. Generally, someone in the middle stage of the disease shows more intense signs of dementia, or memory loss. They may commonly confuse words, experience mood swings or become angry or frustrated, and forget important information like where they live, what day it is, or where they are.
Severe (late stage)
As the disease progresses throughout the brain, symptoms become much worse. In the later stages, individuals with severe Alzheimer’s disease require 24/7 care. Affected individuals usually don’t understand where they are, lose the ability to have a conversation, and experience difficulties walking, sitting, and swallowing.
When it comes to the different Alzheimer’s stages and life expectancy, it’s important to note that the rate of progression between the four stages varies a lot between different individuals. Often, the severity of the disease at the time of diagnosis has a big impact on the individual's life expectancy.