The Facts You Need to Know about Alzheimer’s Disease

Although most people have heard of Alzheimer’s disease, many myths and misconceptions surround the condition. Here’s a look at the disease’s symptoms, potential genetic links, and the history of its discovery.

Alzheimer’s disease was first described in 1906 by the German physician Alois Alzheimer.

Dr. Alzheimer is credited with linking physical symptoms of medical conditions with microscopic brain changes. He outlined the case of Auguste Deter, a patient who was experiencing profound memory loss along with worsening psychological symptoms, including unfounded suspicions of her family members. It was a colleague, Dr. Emil Kraepelin, who first coined the term “Alzheimer’s disease” in his book Psychiatrie.

Following Auguste’s death, Dr. Alzheimer observed dramatic shrinkage of her brain and abnormal deposits in nerve cells while performing her autopsy. The German physician died in 1915, without ever knowing the impact his encounter with Auguste would have on the world. His research was the early spark that ignited a massive international research effort into the disease.

Dr. Alzheimer is esteemed throughout the medical world today not just for his groundbreaking characterization of the condition, but as a role model. He raised the bar in terms of understanding neurodegenerative disorders by building a close clinical relationship with his patient, and by using scientific tools to determine how symptoms correlated with physical brain changes.

Alzheimer’s is a chronic disease for which there is currently no cure.

Its symptoms generally appear gradually, sparking degenerative changes and resulting in a slow decline in cognitive function. There is currently no cure for Alzheimer’s disease; patients’ average life expectancy after diagnosis is three to nine years. However, certain treatments have been shown to slow the progression of the disease and improve quality of life for patients.

Older adults are at higher risk of developing Alzheimer’s disease.

These include people ages 65 and older, as well as people with a family history of Alzheimer’s disease.

People with no known link to Alzheimer’s can develop the condition, but research shows that people with a sibling or parent affected by Alzheimer’s face an increased risk of developing the disease. Those with more than one first-degree relative affected by Alzheimer’s have an even higher risk.

When conditions like Alzheimer’s disease and other forms of dementia run in families, this is largely attributed to genetics, though in certain circumstances environmental factors can come into play.

Scientist have identified several genes that appear to increase an individual’s risk of developing Alzheimer’s disease. The first is the APOE-e4 gene, which appears to have the strongest impact on risk. Experts estimate that up to 65% of individuals with Alzheimer’s have the APOE-e4 gene.

There are several different forms of APOE gene, including APOE-e3 and APOE-e2. We each inherit two copies. People who inherit an APOE-e4 gene from either of their parents are more likely to develop Alzheimer’s. Those who inherit two copies of APOE-e4 face an even higher risk. However, even then, developing Alzheimer’s disease is by no means a certainty.

Studies suggest that up to 30% of Americans have one or two copies of APOE-e4.

Most people with Alzheimer’s develop symptoms after the age of 65.

When people younger than 65 develop the condition, specialists refer to this as early onset Alzheimer’s disease.

Inheriting the APOE-e4 gene has been shown to increase the risk of developing early onset Alzheimer’s.

Up to 80% of dementia patients have Alzheimer’s disease.

Though the terms “Alzheimer’s disease” and “dementia” are often used interchangeably, the conditions are not the same. Alzheimer’s is a form of dementia, but not all forms of dementia are caused by Alzheimer’s disease.

The term dementia refers broadly to various conditions that produce symptoms relating to memory loss, confusion, and forgetfulness. As well as Alzheimer’s disease, dementia can be used to describe a variety of conditions that affect cognitive function, including traumatic brain injury, Parkinson’s disease, and various other conditions that cause similar symptoms.

Alzheimer’s disease is a degenerative condition.

People with Alzheimer’s disease display symptoms and behaviors that grow progressively worse over time. These may include:

  • Memory loss that affects daily activities, such as remembering appointments.
  • Problem-solving difficulties.
  • Difficulties carrying out familiar tasks, such as cooking.
  • Problems with writing or speech.
  • Becoming disorientated about their location or the time.
  • Impaired judgement.
  • Personality and mood changes.
  • Reduced socialization and withdrawal from family, friends, and community.

Alzheimer’s disease consists of seven distinct stages.

At stage 1, there are no symptoms, though Alzheimer’s disease may be diagnosed early based on family history. Through stage 3, the patient’s mental decline may be so slight that it is only noticeable by close family and friends.

Many patients are diagnosed at stage 4, when their memory loss and forgetfulness are apparent, but still comparatively mild. At stage 5, the patient often requires help with daily tasks from a family member or professional caregiver. By stage 7, the disease has advanced to its final and most severe stage. Patients may lose the ability to speak or make facial expressions.

The Alzheimer’s Association was created to eradicate Alzheimer’s disease.

The organization works to increase early detection, advocate for Alzheimer’s research, and provide care and support to people diagnosed with Alzheimer’s and their families.

The Alzheimer’s Association is credited with accelerating global research into the condition. It is the largest nonprofit funder of Alzheimer’s research, with $208 million currently invested in nearly 600 research initiatives around the globe.

About Mark Stevens

Mark Stevens

Based in Menlo Park, California, Mark Stevens is a venture capitalist with three decades of experience investing in the technology industry. Currently, he serves as managing partner of S-Cubed Capital and as a special limited partner of Sequoia Capital.  Continue.