How Long Does Each Stage of Dementia Last?

How long does each stage of dementia last? There is no fixed timetable, but published estimates give a rough shape. The Alzheimer’s Association says a person with Alzheimer’s lives four to eight years after diagnosis on average, and can live as long as 20 years, with the middle stage usually the longest. Estimates based on Dr. Barry Reisberg’s seven-stage scale put stage 4 at about 2 years, stage 5 at about 1.5 years and stage 6 at about 2.5 years.

Those numbers are averages from groups of people. Your parent or partner may move faster or slower, and the pace can change along the way. For the symptoms of each stage in detail, see our article on the stages of dementia. Here, the focus is time: how long, what changes the pace, and how to plan ahead.

How many stages of dementia are there?

The three-stage model. The Alzheimer’s Association describes Alzheimer’s as progressing slowly in three stages: early, middle and late. In a medical setting these are often called mild, moderate and severe.

The seven-stage model. The Global Deterioration Scale (GDS) was developed by Dr. Barry Reisberg, director of the Fisher Alzheimer’s Disease Education and Research program at NYU Grossman School of Medicine. It runs from stage 1, no impairment, to stage 7, the most severe dementia. A related tool, the Functional Assessment Staging procedure (FAST), splits the same course into 16 stages and substages that line up with the GDS stages. When a doctor or care team mentions “stage 5” or “stage 6”, they usually mean one of these seven-stage scales.

How long does each stage of dementia last? A stage-by-stage table

The table maps the seven GDS/FAST stages onto early, middle and late. The mapping is approximate, because stages overlap. Where no source we checked gives a length, we say so rather than guess.

A word of caution about the stage 4 to 6 figures. When Komarova and Thalhauser studied the records of 648 people with Alzheimer’s, the averages they found were somewhat longer than the published estimates, and the spread was huge: for stages 4 and 5, the variation between people was about as large as the average itself.

How long does dementia last overall?

The figures differ by source and by type of dementia.

• Alzheimer’s Association: on average, four to eight years after an Alzheimer’s diagnosis, and as long as 20 years, depending on other factors.
• Cleveland Clinic: points to one study in which people with Alzheimer’s lived about 5.8 years after diagnosis.
• National Alzheimer’s Coordinating Center data (Armstrong and colleagues, 2022): median survival was 6 years for Alzheimer’s, 5 years for frontotemporal lobar degeneration, and 4 years each for vascular dementia and Lewy body dementia.

Keep in mind that these clocks start at diagnosis. The Fisher Center notes that brain changes may begin decades before symptoms are noticeable.

How long does stage 5 dementia last?

Stage 5 is the start of moderate dementia, the point at which the Fisher Center says a person may no longer be able to live independently. The estimate cited by Komarova and Thalhauser puts it at about 1.5 years, and their own analysis agreed that stage 5 tends to be the shortest of stages 4, 5 and 6.

Shorter does not mean easier. Stage 5 is often when the question of whether Mom or Dad can stay home alone becomes urgent. Our article on a person with dementia living alone covers the warning signs and what to put in place.

How long does stage 6 dementia last?

Stage 6 is often the longest single stage. The estimate cited by Komarova and Thalhauser is about 2.5 years, and in their study stage 6 came out longer still, with a wide range from person to person.

Stage 6 is when hands-on help with dressing and bathing usually begins, and when mood and personality changes can be hardest on a spouse. Cleveland Clinic says sundowning begins in the middle and later stages of Alzheimer’s. The Alzheimer’s Association describes it as increased confusion from dusk through the night, and Cleveland Clinic says it usually continues as long as its triggers continue. Our article on what stage of dementia sundowning is explains what helps.

How long does the last stage of Alzheimer’s last?

The Alzheimer’s Association says the late stage of Alzheimer’s may last from several weeks to several years. Komarova and Thalhauser were not able to estimate a length for stage 7 at all, because the data on this stage was too incomplete.

In this stage, a person needs constant help with all daily activities, and comfort becomes the main goal. The Alzheimer’s Association says people can still benefit from relaxing music or reassurance through gentle touch, and that hospice can be of great benefit to people in the final stages and their families. It is worth asking the doctor about hospice early rather than in a crisis. Our article on late-stage dementia goes into the day-to-day care.

If you are reading this because someone you love is in this stage, please be gentle with yourself. There is no right way to feel, and asking for help is not giving up.

What affects how fast dementia progresses?

No one can predict one person’s timeline exactly, but research points to several things that shift it.

The type of dementia. In the coordinating center data, dementia type was one of the strongest predictors of death within five years, with higher risk for the non-Alzheimer’s dementias.

The pattern differs too. The Alzheimer’s Association says vascular dementia can cause sudden changes after a stroke, or more gradual changes as small vessel damage builds up. Dementia with Lewy bodies can bring fluctuating, delirium-like thinking from day to day. Frontotemporal dementia often starts younger: the Alzheimer’s Association says most people with its two main forms are between 45 and 65.

Age at diagnosis. A 2012 review by Brodaty and colleagues found that survival after diagnosis varies considerably. The relative loss of life expectancy was smaller the older a person was at diagnosis, except in frontotemporal dementia and dementia with Lewy bodies. In the coordinating center data, older age was linked to higher risk of death in the non-Alzheimer’s dementias.

Other health conditions. Cleveland Clinic says doctors estimate life expectancy by looking at overall health, other medical conditions and how advanced the symptoms are, and that people in good general health may live longer. The coordinating center study also found male sex, worse cognitive scores in some types, and more depression in Lewy body dementia were linked to higher risk.

Infections, delirium and hospital stays. This is the factor families can most often act on. A 2009 study in Neurology by Fong and colleagues found that after an episode of delirium, the rate of cognitive decline in people with Alzheimer’s sped up, roughly doubling in that group. A separate 2009 study by Holmes and colleagues linked acute infections and other inflammatory illnesses to a 2-fold increase in the rate of cognitive decline over six months.

Cleveland Clinic lists serious illness or infection, surgery or a hospital stay, new pain, poor sleep and too many medicines among the triggers for delirium. Our article on delirium in dementia explains how to spot it.

Stages overlap, and that is normal

The Alzheimer’s Association says it may be difficult to place a person in a specific stage because stages may overlap, and each person may progress differently. Your wife might have a clear morning and a confused evening, or your dad might still shower alone but no longer manage his bills.

So use the stages as a planning map, not a countdown. For a rough sense of where your family member is now, our free dementia stage checker asks a few plain questions about daily life. It is not a diagnosis, but it is a useful start for a talk with the doctor.

Planning care at home as the stages change

The help a person needs usually grows in steps that track the stages. Thinking one stage ahead gives you time to set things up calmly.

• Early stage (stages 3 and 4): the person may still function independently. A few hours a week of company can help with appointments, errands and hobbies. It is also the time to talk about wishes, legal papers and money while your loved one can take part.
• Middle stage (stages 5 and 6): supervision becomes the main need. A steady routine, help getting washed and dressed, and someone present at the times things tend to go wrong. Family caregivers also need regular breaks, and respite helps spouses keep going through the longest stage.
• Late stage (stage 7): constant help with every daily activity. Many families pair hospice or medical care with non-medical support at home, so a familiar face is there for meals, comfort and company.

Our article on how many hours of care dementia needs breaks this down by stage.

At Dementia Companions, we offer non-medical companion care in Florida homes. Our companions with dementia care experience help with routine, supervision, meals, personal care, safe activity and respite for family. Hourly care is $35 an hour, minimum 25 hours a week, and live-in care is from $375 a day. You can read more about dementia companion care or call us at (689) 333-6079 to talk through what would help your family right now.

When a sudden change means call the doctor

Dementia usually changes slowly, over months. A change over hours or days is different, and it can be a sign of something treatable. Cleveland Clinic describes delirium as a sudden change in thinking and awareness that develops over hours to days. Call the doctor promptly if you notice:

• Sudden new or much worse confusion, drowsiness or agitation
• New hallucinations, or a sharp swing between alert and very confused
• Fever, a cough, burning when urinating or other signs of infection
• A fall, new pain, or not eating or drinking
• Changes after a new medicine, a surgery or a hospital stay
• A sudden loss of speech, movement or strength on one side, which needs emergency care right away

Do not assume a sudden drop is simply the next stage. Delirium often has a treatable cause, such as an infection, and given the research above on faster decline after delirium, acting quickly matters.

Sources

• Alzheimer’s Association. Stages of Alzheimer’s.
• Alzheimer’s Association. Early Stage Caregiving.
• Alzheimer’s Association. Middle Stage Caregiving.
• Alzheimer’s Association. Late Stage Caregiving.
• Alzheimer’s Association. Sleep Issues and Sundowning.
• Alzheimer’s Association. Vascular Dementia.
• Alzheimer’s Association. Dementia with Lewy Bodies.
• Alzheimer’s Association. Frontotemporal Dementia.
• Cleveland Clinic. Dementia.
• Cleveland Clinic. Delirium.
• Cleveland Clinic. Sundown Syndrome (Sundowning).
• Fisher Center for Alzheimer’s Research Foundation. 7 Clinical Stages of Alzheimer’s.
• Komarova NL, Thalhauser CJ. High Degree of Heterogeneity in Alzheimer’s Disease Progression Patterns. PLoS Computational Biology, 2011.
• Armstrong MJ, Song S, Kurasz AM, Li Z. Predictors of Mortality in Individuals with Dementia in the National Alzheimer’s Coordinating Center. Journal of Alzheimer’s Disease, 2022.
• Brodaty H, Seeher K, Gibson L. Dementia time to death: a systematic literature review on survival time and years of life lost in people with dementia. International Psychogeriatrics, 2012.
• Fong TG, Jones RN, Shi P, et al. Delirium accelerates cognitive decline in Alzheimer disease. Neurology, 2009.
• Holmes C, Cunningham C, Zotova E, et al. Systemic inflammation and disease progression in Alzheimer disease. Neurology, 2009.