Alzheimer's Disease

Alzheimer’s disease is the most common form of dementia, which is a brain disorder that reduces memory and thinking ability. It is characterized by a gradual reduction in cognitive function and behavioral ability to an extent that greatly impacts daily tasks. Individuals with early stages of Alzheimer’s disease may experience mild memory loss. As the disease progresses, these individuals will lose their ability to perform daily tasks or carry out a conversation, and experience behavioral changes such agitation and delusion. You may be at increased risk of epileptic seizures.¹² Eventually, as the disease becomes more severe, individuals will become unresponsive and require around-the-clock care.¹

Currently, over 7 million Americans live with Alzheimer’s disease. Roughly 1 in 3 older adults die with Alzheimer’s or another form of dementia, and it kills more than breast cancer and prostate cancer combined. Deaths from other chronic diseases have declined in the past few years, while deaths from Alzheimer’s have increased by 142%. In a lifetime, the risk for Alzheimer’s at age 45 is 1 in 5 for women and 1 in 10 for men. Alzheimer’s is a growing public health concern that impacts a considerable proportion of the American population.⁷

The ultimate cause of AD is still unknown. However, there are a variety of factors involved in developing Alzheimer’s disease, such as amyloid deposits and tau tangles, age, genetics, and health/lifestyle habits. 

Recent research suggests that amyloid deposits and tau tangles in your brain are correlated with the onset of Alzheimer’s symptoms. Amyloid deposits are created by beta-amyloid proteins building up into sticky plaques between nerve cells, while tau tangles are developed when tau proteins twist into harmful tangles inside the cells. Together these abnormalities disrupt normal brain function. Deposits interfere with communication between neurons, and tangles block the transport of nutrients within them, ultimately leading to cell damage and death. As these plaques and tangles accumulate over time, they progressively impair memory, thinking, and behavior, causing the symptoms seen in Alzheimer’s disease.  

A very well-known risk factor for Alzheimer’s is age, with most people developing the disease when they are 65 years or older. According to the NIH, 1 in 13 people aged 65 to 84 and 1 in 3 people aged 85 and older live with Alzheimer’s disease. While this is the most well-known risk factor, scientists are still working to understand why it largely impacts older adults. Alzheimer's disease is the biological process that begins with the appearance of a buildup of proteins in the form of amyloid plaques and neurofibrillary tangles in the brain. This causes brain cells to die over time and the brain to shrink.³  

Variations in genes passed down from your parents are another key driver for developing Alzheimer’s. While there is not a single genetic cause, Alzheimer’s can be influenced by multiple genes in combination with lifestyle and/or environmental factors that a person interacts with over time. One gene that influences Alzheimer’s disease is called the apolipoprotein E (APOE) gene. This gene is responsible for making protein that is in charge of carrying cholesterol and other fat into the bloodstream. The APOE gene comes in many different variations depending on the genes passed on from your parents, and each variation holds a different risk profile for developing Alzheimer’s. Other genes that are known to cause Alzheimer’s disease include the amyloid precursor protein (APP) on chromosome 21, presenilin 1 (PSEN1) on chromosome 14 and presenilin 2 (PSEN2) on chromosome 1.  

Lastly, health and lifestyle choices contribute to Alzheimer’s disease risk as well. For example, certain medical conditions, such as hearing loss, depression, mild cognitive impairment and/or concussion/traumatic brain injury, hypertension, and dyslipidemia are associated with higher risk of developing Alzheimer’s. Additionally, addressing certain lifestyle habits, including physical inactivity, alcohol misuse, smoking, social isolation, lack of mental stimulation, lack of/poor sleep or unmanaged health issues, may promote better brain health and reduce your risk for Alzheimer’s disease.⁵

Alzheimer’s disease has a wide array of risk factors, some of which can be changed, while others are fixed. For example, age, sex and genes are risk factors for Alzheimer’s, but cannot be changed. Individuals who are older and of female sex have a higher risk of developing Alzheimer’s. Additionally, as discussed in the FAQ above, certain genes influence the risk of disease. Common risk factors that can be controlled/changed include lifestyle habits and health conditions.⁶

Alzheimer’s disease should be properly diagnosed by a trained healthcare professional. To receive an accurate diagnosis, your healthcare provider will likely assess your memory and thinking ability through testing, identify any changes in personality or behavior, understand the degree of any new memory or thinking impairment, inquire about how thinking impairment has impacted your daily functioning and learn about the cause of your symptoms. It is not uncommon for a healthcare professional to utilize tests, such scans or lab tests for blood-based biomarkers, brain imaging tests or detailed memory testing, before offering a diagnosis. 

Common memory loss testing includes mental status testing, neuropsychological tests, and interviews with family and friends. Mental status testing focuses on your thinking ability and memory to understand the degree of cognitive impairment. Scores on these tests can also be compared to future test scores to understand the level of disease progression over time. Neuropsychological tests involve deeper testing of cognitive ability, where a healthcare professional may test an individual’s ability to take medications as scheduled or manage finances. Lastly, interviews with family and friends allow healthcare professionals to understand whether the degree of cognitive impairment is noticeable to your peers and in what capacity.⁸

Alzheimer’s disease is a progressive disease that is typically described through 4 stages:  

1) Preclinical stage  

• Characterized by changes in the brain that begin years before symptoms are noticed. This stage may last for several years. 

2) Mild, early stage  

• Characterized by mild forgetfulness, which often comes with aging. However, this mild forgetfulness may be accompanied by difficulty concentrating. A person at this stage is likely still able to live independently, but has trouble recalling recent events, remembering a name, or making plans.  

3) Moderate, middle stage 

• Characterized by increasing trouble remembering events, problems learning new things, or trouble remembering their own name, but not details about their own life. As the disease progresses in this stage, an individual may not remember the names of family or friends, lose track of a place or the time, or need help with daily activities such as getting dressed or brushing their teeth. This is typically the longest stage. 

4) Severe, late stage  

• Characterized by losing physical abilities such as walking or eating, losing bowel or bladder control, inability to have a conversation, or being unaware with recent experiences or their surroundings.⁹ 

Being an everyday caregiver for someone with Alzheimer’s is a great undertaking that requires a large amount of responsibility. Caregivers will need to ensure consistent organization of the individuals to-do lists and appointments, plan daily activities, dress and bathe the individual, along with plenty of other tasks that will allow for increased quality of life.

Additionally, caring for someone with Alzheimer’s requires extensive patience as it can be difficult to communicate with an individual who may become frustrated, agitated, or angry if they are consistently unable to remember certain things. It is crucial to reassure the individual and speak calmly to allow the patient to feel understood. Supplying healthy meals and staying active is also a key part of caring for someone with Alzheimer’s, as these factors will allow them to maintain a healthy lifestyle.¹⁰

Please visit the following link if you are in need of resources related to caring for someone with Alzheimer’s disease: https://www.alzheimers.gov/life-with-dementia/resources-caregivers.¹¹

Researchers are continuously investigating potential new and more effective treatments. For guidance on the best treatment options for you—and to determine if you may qualify for a clinical trial—please speak with your healthcare provider.