Stages of Alzheimer’s & Dementia: Durations & Scales Used to Measure Progression (GDS, FAST & CDR)

Last Updated: April 24, 2020


Stages of Dementia

Health professionals often discuss dementia in “stages,” which refers to how far a person’s dementia or Alzheimer’s disease has progressed. Defining the stage helps physicians determine best treatments and aids communication between doctors and caregivers. Dementia is usually considered as three stages: mild (or “early”), moderate (or “middle”), and severe (or “late”). A more specific stage of dementia, however, is commonly assigned based on symptoms.

It can also be helpful to know how symptoms change over stages. Alzheimer’s and similar diseases can cause dramatic swings in mood and behavior, and the activities a person is physically able to do will change as dementia progresses. This causes stress for friends and relatives, but knowing what’s coming can help prepare for social, medical, and personal needs.

In this article we discuss the stages based on various established scales, including symptoms particular to each stage. There is also advice on caring for someone based on their stage of dementia, including technology that can help and which types of assisted living homes are most appropriate.

 Which Stage?  If you aren’t sure which stage of dementia you or your loved one are in right now, take an online Alzheimer’s test that pinpoints an individual’s symptoms and stage.


Is It Dementia? If you want to know whether you or a loved one’s forgetfulness is simply part of aging or is actually dementia, try the Clock Test or SAGE Test.  


Scales for Rating Dementia

Rather than simply using “early stage,” “middle-stage,” and “late-stage” dementia as descriptors, there are scales that provide a more comprehensive description. These scales help better understand the different stages of Alzheimer’s disease based on how well a person thinks (cognitive decline) and functions (physical abilities). These scales are the Global Deterioration Scale for Assessment of Primary Degenerative Dementia, the Functional Assessment Staging Test, and the Clinical Dementia Rating.

 Did You Know? Persons with Alzheimer’s or dementia can receive free assistance finding home care providers or memory care residences that match their care needs, budget and location requirements. 


Global Deterioration Scale / Reisberg Scale

The most commonly used scale is often referred to simply as GDS, or by its more formal name, the Reisberg Scale (or by the lengthy name “Global Deterioration Scale for Assessment of Primary Degenerative Dementia”). The GDS divides into seven stages based on the amount of cognitive decline. This test is most relevant for people who have Alzheimer’s disease because some other types of dementia (i.e. Frontotemporal dementia) do not always include memory loss.

Someone in stages 1-3 does not typically exhibit enough symptoms for a dementia diagnosis. By the time a diagnosis has been made, a dementia patient is typically in stage 4 or beyond. Stage 4 is considered “early dementia,” stages 5 and 6 are considered “middle dementia,” and stage 7 is considered “late dementia.”

Global Deterioration Scale (CGS) / Reisberg Scale
Diagnosis Stage Signs and Symptoms Expected Duration of Stage
No Dementia Stage 1:
No Cognitive Decline
– Normal function
– No memory loss
– People with NO dementia are considered in Stage 1
No Dementia Stage 2:
Very Mild Cognitive Decline
– Forgets names
– Misplaces familiar objects
– Symptoms not evident to loved ones or doctors
No Dementia Stage 3:
Mild Cognitive Decline
– Increased forgetfulness
– Slight difficulty concentrating
– Decreased work performance
– Gets lost more frequently
– Difficulty finding right words
– Loved ones begin to notice
Average duration of this stage is between 2 years and 7 years.
Early-stage Stage 4:
Moderate Cognitive Decline
– Difficulty concentrating
– Forgets recent events
– Cannot manage finances
– Cannot travel alone to new places
– Difficulty completing tasks
– In denial about symptoms
– Socialization problems: Withdraw from friends or family
– Physician can detect cognitive problems
Average duration of this stage is 2 years.
Mid-Stage Stage 5:
Moderately Severe Cognitive Decline
– Major memory deficiencies
– Need assistance with ADLs (dressing, bathing, etc.)
– Forgets details like address or phone number
– Doesn’t know time or date
– Doesn’t know where they are
Average duration of this stage is 1.5 years.
Mid-Stage Stage 6:
Severe Cognitive Decline (Middle Dementia)
– Cannot carry out ADLs without help
– Forgets names of family members
– Forgets recent events
– Forgets major events in past
– Difficulty counting down from 10
– Incontinence (loss of bladder control)
– Difficulty speaking
– Personality and emotional changes
– Delusions
– Compulsions
– Anxiety
Average duration of this stage is 2.5 years
Late-Stage Stage 7:
Very Severe Cognitive Decline (Late Dementia)
– Cannot speak or communicate
– Require help with most activities
– Loss of motor skills
– Cannot walk
Average duration of this stage is 1.5 to 2.5 years.


Functional Assessment Staging Test (FAST)

The Functional Assessment Staging Test (FAST) is another scale that describes the stages of dementia. Like the GDS Scale, FAST is a seven-stage system based more on one’s level of functioning and ability to perform activities of daily living (ADLs) than on cognitive decline. Note: A person may be at a different stage cognitively (GDS stage) than functionally (FAST stage).

Functional Assessment Staging Test (FAST)
Stage Patient Condition Level of Functional Decline Expected Duration of Stage
Stage 1 Normal adult No functional decline. N/A
Stage 2 Normal older adult Personal awareness of some functional decline. Unknown
Stage 3 Early Alzheimer’s disease Noticeable deficits in demanding job situations. Average duration of this stage is 7 years.
Stage 4 Mild Alzheimer’s Requires assistance in complicated tasks such as handling finances, traveling, planning parties, etc. Average duration of this stage is 2 years.
Stage 5 Moderate Alzheimer’s Requires assistance in choosing proper clothing. Average duration of this stage is 1.5 years.
Stage 6 Moderately severe Alzheimer’s Requires assistance with dressing, bathing, and toileting. Experiences urinary and fecal incontinence. Average duration of this stage is 3.5 months to 9.5 months.
Stage 7 Severe Alzheimer’s Speech ability declines to about a half-dozen intelligible words. Progressive loss of ability to walk, to sit up, to smile, and to hold head up. Average duration of this stage is 1 year to 1.5 years.


Clinical Dementia Rating (CDR)

The Clinical Dementia Rating (CDR) scale uses a five-point system based on cognitive (thinking) abilities and how well a person functions. This scale is widely used in dementia research, not as a tool for communication between medical professionals, patients, and their families.

Someone with suspected dementia is evaluated in six areas: Memory, orientation, judgment and problem solving, community affairs, home and hobbies, and personal care. Based on interviews with the subject and others, including family members, one of five possible stages is assigned.

Clinical Dementia Rating (CDR) Scale
Stage Description Expected Duration of Stage
CDR-0 No Dementia N/A
CDR-0.5 Very Mild Dementia – Memory problems are slight, but consistent.
– Some difficulty with time and problem solving
– Daily life is slightly impaired
– Individuals can perform personal care activities
Average duration is a few years up to 7 years.
CDR-1 Mild Dementia – Memory loss is moderate, especially for recent events, and interferes with daily activities.
– Moderate difficulty with solving problems
– Cannot function independently at community affairs
– Difficulty with daily activities and hobbies, especially complex ones
Average duration is 2 years.
CDR-2 Moderate Dementia – More profound memory loss, only retaining highly learned material.
– Disorientation with respect to time and place
– Impaired judgment, with difficulty handling problems
– Little to no independent function at home
– Can only do simple chores
– Fewer interests
Average duration is just under 2 years to 4 years.
CDR-3 Severe Dementia – Severe memory loss.
– Disorientation with respect to time or place
– No judgment or problem solving abilities
– Cannot participate in community affairs outside the home
– Requires help with all tasks of daily living
– Requires help with most personal care
– Frequent incontinence
Average duration is 1 year to 2.5 years.


Duration of Stages: How Long do the Stage of Alzheimer’s / Dementia Last

No two people with dementia experience the disease exactly the same way, and the rate of progression will vary by person and type of dementia. In addition, it is not uncommon for individuals to have mixed dementia, meaning they have more than one type. That said, there is a natural course of the disease, and over time the capabilities of all persons with dementia will worsen. Eventually, the ability to function goes away. Keep in mind that changes in the brain from dementia begin years before diagnosis, when there are no outward symptoms. This makes it difficult to know how much time a person has left, though there are ways (like an Alzheimer’s Life Expectancy Calculator that is under development) to come close to knowing life expectancy.

Life Expectancy by Dementia Type
Dementia Type Life Expectancies
Alzheimer’s Disease 10 years following diagnosis
Vascular Dementia 5 years following diagnosis
Dementia with Lewy Bodies 2 to 8 years following pronounced symptoms

Mild Dementia
In this early stage of dementia, an individual can function rather independently, and often is still able to drive and maintain a social life. Symptoms may be attributed to the normal process of aging. There might be slight lapses in memory, such as misplacing eyeglasses or having difficulty finding the right word. Other difficulties may include issues with planning, organizing, concentrating on tasks, or accomplishing tasks at work. This early stage of dementia, on average, lasts between 2 and 4 years.

Moderate Dementia
In this middle stage of dementia, often the longest stage of the disease, brain damage causes a person to have difficulty expressing thoughts and performing daily tasks. Memory issues are more severe than in the earlier stage. Someone in this stage might forget their address, be unable to recall personal history, and become confused about where they are. Communication becomes harder. The individual may lose track of thoughts, may be unable to follow conversations, and may have trouble understanding what others are saying. Mood and behavior changes—including aggressiveness, difficulty sleeping, depression, paranoia, repeating actions or words, hoarding, wandering, and incontinence—may be seen. This moderate stage of dementia, on average, lasts between 2 and 10 years.

Severe Dementia
In late-stage dementia, also known as advanced dementia, individuals have significant issues with communication. They may not verbally communicate at all. Memory also worsens, and individuals may not be able to remember what they had for lunch. They might forget family members’ names. It’s possible they may think they are in a different time period altogether and revert back to their childhood days. It may be too difficult to walk, and extensive help is needed for daily living activities, including personal hygiene and eating. At the end of this stage, the individual will most likely be bedridden. This severe stage of dementia lasts approximately 1 to 3 years.


What are Specific Care Needs at Each Stage?

An individual may not require care assistance after the initial diagnosis of dementia, but that will change as the disease progresses and symptoms become worse. There are about 16 million unpaid caregivers of people with dementia in the United States. While many caregivers are providing daily help for family members, they also hire someone to help. There are many options of care assistance, such as in-home care, adult day care, and nursing home care. There is also financial assistance available.

Early Stage Dementia
As mentioned above, in the early stage of dementia a person can function rather independently and requires little care assistance. Simple reminders of appointments and names of people may be needed. Caregivers can also assist with coping strategies to help loved ones remain as independent as possible, such as writing out a daily to-do list and a schedule for taking medications. Safety should always be considered, and if any tasks cannot be performed safely alone, supervision and assistance should be provided. During this period of dementia, it’s a good idea for caregivers and loved ones to discuss the future. For example, a long-term care plan should be made and financial and legal matters put in place.

Middle Stage Dementia
In the middle stage of dementia, an individual loses some independence. Assistance with activities of daily living, such as bathing, grooming, and dressing is often required. Initially, an individual may only need prompts or cues to perform these tasks, such as reminders to shower or having clothes laid out on the bed. However, at some point more hands-on assistance will be required. Establishing a routine becomes important, and caregivers need to exercise patience. Since individuals in this stage of dementia have greater difficulty communicating, caregivers need to talk slowly, clearly, and use non-verbal communication. Individuals will no longer be able to drive, so transportation will be required. It is also in this stage of dementia when it becomes unsafe to leave the individual alone, which means supervision is necessary.

Late Stage Dementia
A person in this last stage of dementia requires a significant amount of care. Assistance and supervision is required 24 hours per day. Dementia patients may require assistance getting in and out of bed, moving from the bed to a chair, or may be bedridden and require help changing positions to avoid bedsores. Swallowing becomes an issue in late-stage dementia, and caregivers have to make sure food is cut into small pieces, is soft (like yogurt and applesauce), or is pureed. At some point, the individual will be 100% dependent on their caregiver and will no longer be able to complete any daily living activities alone. Not all families are equipped to offer this level of care. As mentioned previously, there are other options for care, such as hiring a part time caregiver or moving your loved one to a nursing home.

  For more information on caring for individuals with dementia, click here. It’s important to remember, providing care for a loved one can be stressful, and self-care is a must. Click here to learn about ways to deal with stress, finding support, and more.


Where to Live with Dementia?

Eventually, caregiving for someone with dementia won’t be appropriate anymore. The needs of a person with progressive dementia (like Alzheimer’s disease) become overwhelming, and moving into a full-time residence with trained staff becomes necessary. You should plan for this well before it becomes necessary, by visiting communities and asking the right questions.

Depending on your loved one’s stage of illness, different living options are available:

Assisted Living in Early Stages
Assisted living residences combine room and board with medical and personal care, and are often sufficient for someone in the early stages of Alzheimer’s disease or related dementia. Full-time supervision means residents are safe, with living units like private studios or apartments so someone with mild dementia can still feel a sense of independence.

Services offered in assisted living include meals, help with activities of daily living (ADLs), social activities, and transportation to and from doctor’s appointments. Before moving in, the residence will assess your loved one to make sure it’s a good fit.

Memory Care in Middle to Late Stages
Some assisted living residences offer memory care, also called “Special Care Units” or “Alzheimer’s Care Units.” Memory care is better for someone in the middle stages of dementia, when independence has become more difficult or even impossible. Memory care can be a wing or special section of assisted living, or there are stand-alone memory care homes. These are more appropriate for people past the earliest stages because staff is trained specifically to communicate with and care for people whose needs are particular to dementia. Speaking with someone who has dementia requires careful technique. Similarly, activities for people with dementia are more considerate of the participants’ ability (or inability) to function and understand.

Memory care residences have physical designs that are appropriate for people with dementia. Someone with Alzheimer’s, for instance, may become upset when encountering a wall, so memory care buildings have circular hallways. Because people with dementia are prone to wander, memory care residences have increased security and supervision, and special locks on doors.

  Did You Know? Assisted living homes, including those with memory care, cannot take someone whose needs are too great for the residence. In every state, an assessment is required before moving into assisted living, to determine what kind of care is necessary and whether the residence can provide it. See state-specific regulations.

Nursing Homes
Nursing homes are appropriate for someone with dementia if there are other medical considerations, like if your loved one needs full-time nursing care, needs medical devices like tubes to breathe or eat, or cannot walk. (The ability to evacuate without assistance in an emergency is required by assisted-living regulations in several states.)

Nursing homes are not ideal for someone with advanced dementia unless there are those other medical considerations. Consider that these residences are staffed with trained nurses whose expertise is administering healthcare, while training for staff in assisted living with memory care is specifically to deal with issues related to dementia, like how to communicate when the resident is feeling depressed or withdrawn, and how to encourage socialization. Memory care, therefore, is usually the best option.


Assistive Technology by Stage

Numerous tools and technological aids can make living with dementia easier for people in any stage.

Tech for Early-Stage Dementia

  • Pill boxes to manage medications don’t have to be complex in the early stages, but are a good idea to know that your loved one is taking the right medicine at the right time.
  • Automatic stove/oven turn offs will help when your loved one leaves the stove on. This seems like an absent-minded mistake at first, but it will be more common that a task is started and not finished. With turn offs, your loved one is safer making simple mistakes.
  • Appliance use monitors let concerned friends or family track whether a person with dementia has turned off the oven, coffee maker, or any other electronic device. Monitors are cheap (around $30 typically) and easy-to-use, plugging the device to an outlet and then sending a signal to your smartphone if it’s on for too long. You can even turn off appliances remotely.
  • Object locators or key finders help with the inevitable forgetfulness that many people in early stages experience. A small beeper attaches to the frequently lost item, like the TV remote or eyeglasses, and chirps a signal whenever you press a button on the locator. These often cost around $20.


Tech for Middle-Stage Dementia

  • Medication dispensers become more complex the deeper into dementia you get. For someone who is out of the middle stages, it’s a good idea to invest in a high-tech dispenser that sounds an alarm and provides the correct dosage when it’s time to take certain medicines. These can cost from $60 to hundreds of dollars.
  • Stove knob covers prevent someone from using the stove. A person with slightly more advanced dementia may be in danger of causing an accident like a fire if they’re allowed to cook. (You can also remove the knobs.)
  • Clocks for people with dementia have special features that specifically address issues like disorientation, where a person becomes confused about the time of day. Dementia clocks have large, bright numbers and actually say “Morning” or “Afternoon.” Staying aware of the time of day can help someone maintain bodily (circadian) rhythms and sleep better. These cost about $40 and up.
  • Medical alerts, also known as Personal Emergency Response Systems (PERS), are worn clipped to clothing or on a lanyard and have a button that easily calls for medical help. These are useful for someone at risk of falling, or who might wander and become lost. Alerts often have GPS tracking. Costs vary, and some medical alerts include subscriptions to security services.
  • Talking photo albums can help someone who is losing track of people and names in their family. Pictures in the albums are set next to buttons that play pre-recorded messages explaining who or what is in the image.