Dementia and Alzheimer’s Disease
Where It Started, Where We Are, and What’s Coming Next
STANDARD
In the fall of 1901, a German psychiatrist named Alois Alzheimer sat across from a 51-year-old woman named Auguste Deter in a Frankfurt psychiatric hospital. She couldn’t remember her husband’s name. She called the wrong objects by the wrong names. She woke screaming in the middle of the night. When Alzheimer asked her where she was, she answered: “Here and everywhere. Here and now.” [1]
She was too young for what was happening to her — and Alzheimer knew it. He’d never seen anything quite like it. He followed her case until she died in 1906, then examined her brain. What he found changed medicine permanently.
The First Documented Cases
Dementia itself — the general erosion of memory and cognitive function — had been observed for centuries. Ancient Greek and Roman physicians wrote about it. But the specific disease we now call Alzheimer’s was first formally described on November 3, 1906, when Alois Alzheimer presented his findings at a psychiatric conference in Tübingen. [2]
During the autopsy of Auguste Deter, Alzheimer identified two things nobody had documented before in combination: dense, insoluble protein clumps outside neurons — what we now call amyloid plaques — and twisted, thread-like structures inside neurons composed of what we now call tau protein, forming neurofibrillary tangles. These two pathological features — amyloid plaques and tau tangles — are still the defining characteristics of Alzheimer’s disease more than a century later. [1]
The disease got its name not from Alzheimer himself but from his mentor, the renowned psychiatrist Emil Kraepelin, who named it after his colleague in the 1910 edition of his landmark psychiatry textbook. Initially it referred to presenile dementia — the kind that appeared before old age, like Deter’s case. Later the term expanded to include the more common late-onset version. [3]
Alzheimer died in 1915 at age 51 — the same age as Auguste Deter when she first showed symptoms. He didn’t live to see the disease that bears his name become the most common cause of dementia in the world. [1]
What Dementia Actually Is — and What It Isn’t
Dementia is not a single disease. It’s an umbrella term for a collection of symptoms severe enough to interfere with daily life — memory loss, confusion, trouble with language, difficulty with familiar tasks, changes in personality and judgment.
Alzheimer’s disease is the most common cause, accounting for approximately 60 to 80 percent of all dementia cases. [4] Vascular dementia — caused by damage to the blood vessels that supply the brain — is the second most common type and tends to affect focus, organization, and speed of thinking more than memory initially. Lewy body dementia involves abnormal protein deposits that interfere with brain chemistry and affect behavior, mood, movement, and thinking. Frontotemporal dementia affects the front and sides of the brain — areas that govern personality, behavior, and language — and often presents as dramatic personality changes rather than memory loss. [5]
Understanding which type a person has matters — because the treatments, the progression, and the caregiving approach differ across types.
The Early Warning Signs
This is where the gap between knowing and acting causes the most damage. Half of Americans with Alzheimer’s disease or a related dementia never receive a diagnosis. For those who do, the diagnosis often comes two to five years after symptoms began. [6]
The early signs are easy to dismiss — as stress, as normal aging, as a bad week. They’re not always dramatic. But they’re there.
Memory loss that disrupts daily life is the most recognizable — forgetting recently learned information, asking the same question repeatedly, increasingly relying on memory aids for things that used to come naturally. But it’s the other signs that often get missed.
Difficulty planning or solving problems that were once routine. Trouble completing familiar tasks — getting lost on a route driven hundreds of times, forgetting the rules of a game played for decades. Confusion about time or place — not just forgetting the date, but genuinely losing track of seasons, years, where they are and how they got there.
Word-finding trouble. The right word sitting just out of reach. Withdrawing from social activities or hobbies once enjoyed. Changes in mood or personality that feel uncharacteristic — new anxiety, suspicion, depression, or agitation, particularly in unfamiliar settings. [5]
New cognitive or behavioral changes after age 55 — particularly new-onset depression, word-finding difficulty, or trouble with familiar tasks — warrant evaluation. [7] The key is noticing change from a person’s own baseline, not comparing to a population average.
Early-onset dementia can appear in the 40s and 50s and is less rare than most people assume. If something seems wrong, trust that instinct and get it evaluated — because early diagnosis now means something it didn’t used to mean.
Prevention — What the Evidence Actually Says
There is no guaranteed way to prevent Alzheimer’s disease. The genetics are real — carrying one copy of the APOE4 gene roughly doubles the risk; two copies raises it dramatically. Age is the biggest risk factor of all, and nobody gets to control that.
But modifiable risk factors exist. The Lancet Commission’s 2024 report identified 14 modifiable risk factors that together account for roughly 45 percent of dementia cases worldwide. [8] These include high blood pressure, obesity, physical inactivity, smoking, excessive alcohol consumption, diabetes, depression, social isolation, air pollution, traumatic brain injury, hearing loss, vision loss, and low education in early life.
Physical exercise consistently appears in the prevention research — cardiovascular exercise in particular. Studies suggest regular aerobic exercise may reduce dementia risk by up to 35 percent. [7] Sleep matters more than most people realize. During deep sleep, the brain’s glymphatic system clears metabolic waste — including amyloid proteins. Chronic poor sleep is associated with higher amyloid accumulation.
Diet — particularly the Mediterranean and MIND diets — shows consistent associations with reduced cognitive decline. Social engagement is a genuine protective factor. Loneliness and social isolation are linked to significantly higher dementia risk. [7]
Addressing modifiable risk factors will not guarantee prevention. But the evidence strongly suggests these efforts meaningfully reduce risk.
The New Drugs — What Changed and What It Means
For most of the 20th century and well into the 21st, the drugs available for Alzheimer’s managed symptoms without touching the underlying disease. Cholinesterase inhibitors like donepezil improved neurotransmitter function. Memantine reduced excess glutamate activity. They helped. They didn’t slow the disease itself.
That changed in 2023.
In July 2023, the FDA granted full traditional approval to lecanemab — marketed as Leqembi — the first therapy proven to slow cognitive decline by clearing beta-amyloid plaques from the brain. In a clinical trial of nearly 1,800 participants, lecanemab slowed cognitive decline by 27 percent over 18 months compared to placebo. [9]
On July 2, 2024, the FDA approved donanemab — marketed as Kisunla — showing approximately 35 percent slower disease progression over 18 months compared to placebo, corresponding to roughly a 4.5 to 7.5 month delay on clinical scales. Amyloid plaque levels were reduced by an average of 61 percent at six months and 84 percent at 18 months. [10]
Both drugs work by targeting and clearing amyloid plaques — the same plaques Alois Alzheimer identified in Auguste Deter’s brain in 1906. Both are limited to people in the earliest stages of the disease. Both carry a risk of amyloid-related imaging abnormalities (ARIA) — brain swelling or microbleeds that require regular MRI monitoring and occur in approximately one in five patients. [10]
These are not cures. They slow the disease. But slowing a disease that previously had no disease-modifying treatment is a landmark. [11]
In August 2025, the FDA approved a subcutaneous self-injection formulation of lecanemab — called Leqembi IQLIK — that patients or caregivers can administer at home once weekly, eliminating the need for biweekly clinic infusions. [12]
The pipeline continues to grow. A Phase 2 trial in late 2024 showed personalized, non-invasive brain stimulation slowed cognitive decline by 44 percent in people with mild-to-moderate Alzheimer’s. Blood tests that detect amyloid with more than 90 percent accuracy are already reducing wait times and costs for diagnosis. [13]
Caregiver Resources — You Are Not Alone in This
Caring for someone with dementia is one of the most demanding things a person can do. Caregiver burnout is real and common. Asking for help is not a failure.
The Alzheimer’s Association — alz.org — operates a 24/7 helpline at 1-800-272-3900, offers a community resource finder, care consultation services, and an online support community. Their website includes detailed information on every stage of the disease, legal planning, and financial guidance.
The Alzheimer’s Foundation of America — alzfdn.org — provides free memory screenings, educational webinars, and a toll-free helpline staffed by licensed social workers: 1-866-232-8484.
The Family Caregiver Alliance — caregiver.org — offers comprehensive online resources including care guides, legal and financial planning resources, and a state-by-state resource locator.
The AARP Caregiver Resource Center — aarp.org/caregiving — provides free online tools, articles, and a care guide specifically for dementia caregivers.
The National Institute on Aging — nia.nih.gov/health/alzheimers — offers a searchable directory of clinical trials, plain-language information on diagnosis and treatment, and caregiver education resources.
If you’re in crisis or overwhelmed, the 988 Suicide and Crisis Lifeline now covers caregiver crisis calls as well. You don’t have to be suicidal to call. Caregiver exhaustion and despair are valid reasons to reach out.
The Bottom Line
A German doctor sat with a confused 51-year-old woman in 1901 and paid close enough attention to change everything we know about the brain. More than a century later, the disease he documented is finally — finally — yielding to treatment.
Not quickly enough. Not completely. Not for everyone. But 7.4 million Americans are currently living with Alzheimer’s disease, [5] and for the first time in the history of medicine, there are drugs that slow its progression rather than merely soften its symptoms.
The early signs are knowable. The risk factors are partially modifiable. The resources for caregivers are real and available. And the research — moving faster now than at any point since Alois Alzheimer first presented his findings in Tübingen — is not finished.
Auguste Deter said “I have lost myself.” The people coming after her deserve better. The science is working on it.
Sources
— [1] Being Patient. A Neurologist’s History of First Known Alzheimer’s Patient Auguste Deter. beingpatient.com. May 2025.
— [2] PMC / National Library of Medicine. The Discovery of Alzheimer’s Disease. pmc.ncbi.nlm.nih.gov/articles/PMC3181715
— [3] Optoceutics. Alois Alzheimer — Discovery, Name Origin and Auguste Deter’s Role. optoceutics.com. June 2025.
— [4] ClinicalTrials.gov / NIH. A Phase 1a Study of PMN310 in Healthy Volunteers. NCT06105528. Citing WHO 2023 dementia prevalence data.
— [5] AARP. 15 Early Warning Signs of Dementia and Alzheimer’s. aarp.org. April 2026.
— [6] ClinicalTrials.gov / NIH. Caregiver Outcomes of Alzheimer’s Disease Screening (COADS). NCT03300180. Citing USPSTF data on diagnosis delays.
— [7] HelpDementia.com. Early Warning Signs of Dementia in Women: 2026 Practical Caregiver Guide. helpdementia.com. Citing Lancet Commission 2024 report.
— [8] Livingston G, et al. Dementia Prevention, Intervention, and Care: 2024 Report of the Lancet Standing Commission. The Lancet. Vol. 404, No. 10452, pp. 572–628. 2024.
— [9] Cleveland Alzheimer’s Disease Research Center. New FDA Approved Alzheimer’s Treatments. clevelandadrc.org. May 2026. Citing CLARITY AD trial data.
— [10] FDA. FDA Approves Treatment for Adults with Alzheimer’s Disease — Kisunla (donanemab). fda.gov. July 2, 2024.
— [11] Alzheimer’s Association. Lecanemab (Leqembi) — FDA Approval Information. alz.org
— [12] HelpDementia.com. Newest FDA Approved: 2026 Practical Caregiver Guide — Leqembi IQLIK subcutaneous approval. helpdementia.com.
— [13] BrightFocus Foundation. Expanding the Alzheimer’s Treatment Landscape: A 2026 Forecast. brightfocus.org. March 2026.