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

Stages of Dementia

Health professionals often discuss dementia in terms of “stages.” This refers to how dementia progresses. In general, dementia has three stages: mild (or early), moderate (or middle) and severe (or late). But there are more detailed scales that use five or seven stages of dementia, which are discussed below. These guidelines help doctors and caregivers communicate with each other when diagnosing patients and determining treatments, and they can also help families understand what their loved ones are experiencing and what to expect in the coming months and years.

As dementia progresses through its stages, existing symptoms worsen and new ones emerge. This means the type of care required will also need to change, from different caregivers and technology to relocating to an assisted living facility or nursing home. All of this can prove stressful for family members and friends, but knowing what’s coming can help you prepare for the challenges ahead.

Scales for Rating Dementia

Rather than simply using “mild, moderate and severe,” as dementia descriptors, professionals use more comprehensive systems. These scales take a closer look at cognitive and physical decline in order to separate dementia into more specific stages. The three most common are the Global Deterioration Scale for Assessment of Primary Degenerative Dementia, the Functional Assessment Staging Test and the Clinical Dementia Rating, which are all discussed below.

Global Deterioration Scale / Reisberg Scale

This is the most commonly used scale to delineate dementia stages. Its formal name is the Reisberg Scale, and its lengthy official name is the Global Deterioration Scale for Assessment of Primary Degenerative Dementia. But the simplest way to refer to it is “GDS.”

The GDS divides dementia into seven stages based on cognitive decline, including memory loss. This scale is most relevant for people who have Alzheimer’s disease because some other types of dementia (like Frontotemporal dementia) do not always include memory loss.

Someone in GDS 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 GDS Stage 4 or beyond. GDS Stage 4 is considered “early dementia,” Stages 5 and 6 are considered “middle dementia,” and Stage 7 is considered “late dementia.”

Functional Assessment Staging Test (FAST)

The Functional Assessment Staging Test (FAST) is another scale that delineates the stages of dementia. Like the GDS, FAST is a seven-stage scale, but the FAST stages are based more on the patient’s level of functioning and ability to perform the Activities of Daily Living (ADLs) rather than their cognitive decline, which is the primary factor in the GDS. A person may be at a different stage cognitively (GDS) than functionally (FAST).

Clinical Dementia Rating (CDR)

The Clinical Dementia Rating (CDR) scale uses a five-point system based on both cognitive abilities and functional abilities. how well a person functions. This scale is widely used in dementia research, but it’s not usually used by medical professionals to communicate with each other or with patients and their families.

The CDR evaluates six areas through interviews with the patient, their family members and others: memory, orientation, judgment and problem-solving, community affairs, home and hobbies, and personal care. After the interviews and analysis, the patient is assigned to one of five stages.

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

No two people with dementia experience the disease exactly the same way, so how long the stages last can change on a case-by-case basis. That said, the disease does take a natural course, and over time the capabilities of all dementia patients will worsen. Eventually, they will lose all ability to function. 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 until they lose all ability to function. However, there are ways to estimate, like our Alzheimer’s Life Expectancy Calculator.

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. They might be:

• Slight lapses in memory, such as misplacing eyeglasses or having difficulty finding the right word.
• Planning, organizing, concentrating on tasks, or accomplishing tasks at work.

The early stage of dementia normally lasts between two and four years.

Moderate Dementia

In the 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 or become easily confused about where they are. Communication becomes harder. The individual may lose track of thoughts and conversations, and have trouble understanding what others are saying. They might experience significant swings in mood or behavior, or any of the following symptoms:

• Aggressiveness
• Difficulty sleeping
• Depression
• Paranoia
• Repeating actions or words
• Hoarding
• Wandering
• Incontinence

This moderate stage of dementia, on average, lasts between two and 10 years.

Severe Dementia

In late-stage dementia, also known as advanced dementia, individuals have significant issues with communication. Patients may:

• Lose verbal communication
• Have their memory worsen. Your loved one might forget family members’ names or go back to a different time period altogether and revert to their childhood days.
• Have difficulty walking
• Need extensive help with the Activities of Daily Living: mobility, personal hygiene, eating and toileting.

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?

Individuals may not require care assistance after the initial diagnosis of dementia, but that will change as the disease progresses and symptoms worsen. Many people with dementia rely on unpaid caregivers, like family members. In fact, it’s estimated that there are about 16 million people providing unpaid care to dementia patients in the United States. Eventually, many of these unpaid caregivers will not be able to provide the kind of help the dementia patient needs and they will need to hire paid caregivers. And some dementia patients simply don’t have any family members or friends to provide unpaid care. Financial assistance is available for people who suffer with dementia. That assistance can help with in-home care, adult day care and nursing home care.

Early Stage Dementia
In the early stage of dementia, a person can function rather independently and requires little care assistance. Simple reminders about appointments and names of people may be needed. Caregivers can also assist with coping strategies to help dementia patients remain as independent as possible. That can include things like writing out a daily to-do list or a schedule for taking medications. If any of these tasks cannot be performed alone due to safety concerns, 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, patients start losing their independence. Assistance with the Activities of Daily Living (ADLs), such as bathing, grooming and dressing is normally 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. This stage of dementia is also when constant supervision becomes necessary because it’s unsafe to leave your loved one alone.

Late Stage Dementia

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

Where to Live with Dementia?

Eventually, caregiving for someone with dementia gets to a point where the amount of support they need can not be provided by an unpaid and untrained caregiver. The needs of a person with progressive dementia, like Alzheimer’s disease, usually become so overwhelming that moving into a full-time residence with trained staff becomes the only option. You should plan for this contingency well before it becomes necessary. That is done by researching and visiting long-term care facilities and asking lots of questions.

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

Assisted Living in Early Stages

Assisted living residences combine some independent living with available medical and personal care. These are often great options for someone in the early stages of Alzheimer’s disease or related dementia. Full-time supervision means residents are safe. Housing is provided through 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, social activities, help with ADLs and transportation to and from doctor’s appointments. Before moving in, the residence will assess your loved one and their care needs 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 nearly 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 the staff is trained specifically to communicate with and care for people with 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 also have physical designs that are appropriate for people with dementia. Someone with Alzheimer’s may become upset when encountering a wall, so memory care buildings have circular hallways. Because people with dementia are prone to wandering, memory care residences have increased security and supervision with special locks on doors.

In some states, Medicaid will help cover the cost of long-term care in assisted living residences, including memory care units for qualified individuals, although in most cases Medicaid will not cover room and board in assisted living facilities. In order to qualify, individuals have to meet functional and financial criteria. The functional criteria for most Medicaid programs that provide long-term care in assisted living is requiring a Nursing Facility Level of Care. The financial requirements, in most states in 2025, is meeting an asset limit of $2,000 and an income limit of $2,901/month. Individuals who don’t meet those limits should consult with a professional, like a Certified Medicaid Planner, who can help the applicant maximize their resources and, eventually, qualify for Medicaid.

Nursing Homes

Nursing homes are appropriate for someone with dementia if there are other medical needs. They are best able to support patients who need full-time nursing care, medical devices like tubes to breathe or eat, or cannot walk. The ability to evacuate without assistance in an emergency is a required regulation in several states.

Unfortunately, nursing homes are very expensive. The average cost in the U.S. in 2025 is $10,000/month, although that can vary by location. For individuals who meet the eligibility criteria, the full cost of the nursing home, including room and board, will be covered by Nursing Home Medicaid will cover the full cost of nursing homes, including room board.

Nursing homes are not ideal for someone with advanced dementia unless there are other medical considerations. These residences are staffed with trained nurses whose expertise is administering healthcare. In comparison, training for staff in assisted living with memory care is specifically tailored to deal with issues related to dementia. They focus on how to communicate when a resident is feeling depressed or withdrawn, and how to encourage socialization. For this reason, memory care is usually the best option.

Assistive Technology by Stage

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

Tech for Early-Stage Dementia

• Pillboxes to manage medications don’t have to be complex in the early stages, but it is 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 keep your loved one safe when cooking. This seems like an absent-minded mistake at first, but as dementia progresses starting a task and not finishing it will be more common.
• Use appliance monitors to 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 (typically around $30) and easy to use, plugging the device into 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 early 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 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 say “Morning” or “Afternoon.” Staying aware of the time 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.