Dementia, Alzheimer's and Senility: What are the Differences?

In the realm of cognitive decline, terms like dementia, Alzheimer's disease and senility are often used interchangeably. However, these terms are not the same and refer to distinct conditions with unique characteristics and causes.

“In the setting of an aging population, the number of older adults with dementia is increasing. It’s important to understand the changes associated with normal aging versus the changes associated with a diagnosable neurocognitive disorder,” says Katherine Amodeo, MD, a WMCHealth neurologist based at MidHudson Regional Hospital.

Read about the differences between these often-confused terms to learn more about the nuances of cognitive decline.

Dementia: A Broad Cognitive Impairment

“Dementia is an umbrella term that encompasses a range of neurocognitive disorders that cause memory loss and difficulties communicating, reasoning and problem-solving, with impact on function. It’s not a specific disease but rather a syndrome caused by various underlying conditions that affect brain function,” says Dr. Amodeo, who specializes in dementia and movement disorders.

Dementia is often characterized by a decline in cognitive abilities that impairs an individual's daily functioning and quality of life. Common forms of dementia include Alzheimer's disease, vascular dementia, Lewy body dementia and frontotemporal dementia. “People can also have mixed dementia, with more than one pathology impacting the brain,” says Dr. Amodeo.

Dementia can result from different conditions, and its progression and treatment depend on the underlying cause.

Alzheimer's Disease: A Specific Form of Dementia

Alzheimer's disease is the most common cause of dementia, accounting for around 60-70% of all cases. It’s a progressive neurological disorder that primarily affects memory, thinking and behavior.

“The exact cause of Alzheimer's disease is not fully understood, though genetic predisposition plays a role in risk. It involves the accumulation of abnormal protein deposits in the brain, leading to the death of brain cells and the subsequent deterioration of cognitive function,” says Dr. Amodeo. “The disease follows a relatively predictable pattern of cognitive decline, starting with memory impairment and gradually affecting other cognitive functions.” Early symptoms often include forgetfulness and trouble with word-finding.

As the disease progresses, individuals may experience increasing trouble with memory, language and executive function with a propensity for moments of increased confusion, agitation and hallucinations or delusions—often referred to as “sun-downing.” A cure has yet to be found, but current treatments aim to manage symptoms and slow the progression of the disease.

Katherine Amodeo, MD

Senility: An Outdated Term

Senility is an outdated term historically used to describe age-related cognitive decline in older adults. While some may use “senility” to refer to dementia, that isn’t correct. “When people use the word ‘senile,’ they imply that the serious symptoms of dementia are characteristic of old age when, in fact, they are not a regular part of aging. While most cases of dementia occur in people 65 or older, young people can develop it as well,” says Dr. Amodeo.

Here's What You Can Do to Help Your Loved One

“While not all cognitive decline in older adults is indicative of dementia or Alzheimer's disease, it’s important people know the difference between these terms, especially as it applies to their loved ones,” says Dr. Amodeo. “If you or a loved one is showing signs of a significant decline in cognitive or motor skills, it’s important to see your primary care provider or neurologist for proper diagnosis and treatment if appropriate.”

WMCHealth neurologists specializing in neurodegenerative and movement disorders focus on care and management of adults with Alzheimer’s disease, neurodegenerative dementia, treatable dementia, Parkinson’s disease and other degenerative diseases. To learn more or book an appointment with one of our neurologists, visit our WMCHealth Physicians and Bon Secours Medical Group webpages.