Q: Are Alzheimer’s disease and dementia the same thing?
A: No. Dementia is an umbrella term for changes in memory and thinking that impair how a person functions. Several different underlying diseases can cause dementia. Alzheimer’s disease is one of those diseases.
Dementia is characterized by gradual changes in one or more areas of cognition over time that impact a person’s ability to function in daily life without assistance. It is not a part of normal aging.
Broadly, dementia affects cognition, which includes:
✳️ Memory
✳️ Language
✳️ Planning and organizing
✳️ Vision
✳️ Movement
✳️ Behavior
Alzheimer’s disease is a specific type of dementia that occurs when two proteins – amyloid and tau –become misfolded and build up in the brain, causing brain cells to die. This leads to shrinking (or atrophy) of certain areas of the brain, especially those responsible for memory. Early signs of Alzheimer’s disease are problems with short-term memory. Short-term memory loss could include trouble remembering recent events or difficulty planning and organizing a familiar meal.
Alzheimer’s is the most common type of dementia, accounting for somewhere between 60-80% of cases. However, scientists are learning that most people with dementia have evidence of more than one underlying disease. This is called mixed dementia.
What if it’s not Alzheimer’s?
Several underlying diseases can cause dementia, such as:
🔸 Frontotemporal degeneration (FTD) – This is the most common form of dementia among younger people aged 45 to 60. In most cases, the cause of FTD is not known. Early signs of FTD include changes in personality or behavior, or difficulty producing or understanding language. Unlike Alzheimer’s disease, memory is typically intact. Bruce Willis was recently diagnosed with FTD.
🔸 Lewy body disease (DLB) – DLB is characterized by new sleep disturbances, like acting out dreams, and visual hallucinations. An example of a visual hallucination is seeing bugs crawling up the wall that aren’t there. It can come with movement symptoms, like Parkinson’s disease. Symptoms can change throughout the day. Robin Williams was diagnosed with DLB before his death.
🔸 Parkinson’s disease (PD) – Parkinson’s disease most commonly causes changes in movement, called tremors. Changes in movement can occur alone or accompanied by changes in cognition. When this happens, we call it Parkinson’s disease with dementia. Changes in cognition can occur, before, at the same time, or after the start of movement symptoms. Michael J Fox has lived for decades with PD and does not appear to have symptoms of PD dementia.
🔸 Cerebrovascular disease (CVD) – CVD is caused by damage to the blood vessels of the brain. You may hear people call this a mini stroke. Dementia caused by CVD is called Vascular Dementia. It usually happens suddenly rather than a slow steady decline in cognition. The area of cognition impacted varies depending on the location of the damage in the brain and often looks different from person to person.
Dementia is the 7th leading cause of death worldwide and the only leading cause of death with no treatment that shortens the length of the disease. Around 10% of people over 65 years old have dementia. We expect the number of people diagnosed with dementia to grow as the Baby Boomer generation ages and our ability to detect and diagnose dementia improves. Those Nerdy Girls are working on a series of posts about dementia and cognition over the coming months. Stay tuned for more information.
Additional Reading:
What if It’s Not Alzheimer’s? A Caregiver’s Guide to Dementia, Edited by Lisa Radin & Gary Radin
