What are the stages of dementia, and how do I know which one my parent is in?

Published by Unseen Progress, an independent publisher of caregiver research. Last reviewed 2026-07-10. Part of the dementia caregiver research overview.

Short answer. Dementia is progressive, and clinicians describe its course in three broad stages — early (mild), middle (moderate), and late (severe) — which more formal tools break into finer steps. The two most cited staging instruments are Reisberg's Global Deterioration Scale (GDS) and its functional companion FAST (Reisberg et al., 1982), which run across seven stages, and the Clinical Dementia Rating (CDR) (Morris, 1993), which scores five levels from 0 (none) to 3 (severe). Staging matters less as a label than as a guide: it tells you which abilities to expect, which are likely fading next, and therefore which kind of support actually helps right now (Alzheimer's Association, 2024; Gitlin, Kales, & Lyketsos, 2012).

What the research says

Dementia does not progress in clean, dated steps. It is a slow, individually variable decline, and staging systems are best understood as a shared vocabulary for roughly where someone is — not a countdown clock. The Alzheimer's Association (2024) frames the journey in three practical bands (early, middle, late), while research and clinical practice use more granular scales when a precise reference point is needed.

Two staging tools dominate the literature:

  • Global Deterioration Scale (GDS) and Functional Assessment Staging (FAST) — Reisberg's seven-stage framework (Reisberg et al., 1982), running from stage 1 (no impairment) through stage 7 (very severe decline). GDS emphasises cognition; FAST, derived from the same system, emphasises functional loss (dressing, bathing, continence, ambulation) and is especially used to track the late course.
  • Clinical Dementia Rating (CDR) — Morris's (1993) five-point global scale (0, 0.5, 1, 2, 3), built from an informant interview across six domains: memory, orientation, judgment/problem-solving, community affairs, home and hobbies, and personal care.

The reason these matter to a caregiver is not the number itself. It is that each stage has a characteristic profile of what is still intact and what is slipping — and the research on nonpharmacologic care (Gitlin, Kales, & Lyketsos, 2012) shows that support works best when it is matched to that profile rather than to the disease in the abstract.

The stages at a glance

The table below maps the three practical bands to the more granular tools and to what caregivers typically see. Individual courses vary widely; treat this as orientation, not prediction.

Practical bandGDS / FAST (approx.)CDR (approx.)What families typically seeCare emphasis
Early (mild)GDS 3–4CDR 0.5–1Word-finding gaps, repeated questions, misplaced items, trouble with complex tasks (finances, planning); independent in daily self-careSupport autonomy; set up routines, reminders, legal/financial planning while capacity holds
Middle (moderate)GDS 5–6CDR 2Needs help choosing clothes and with some daily tasks; disorientation to time/place; behavioural changes (agitation, sundowning); may not recognise recent eventsStructure, cueing, safety-proofing; decode behaviour as unmet need; supervise but preserve dignity
Late (severe)GDS 7 / FAST 7CDR 3Extensive help with all self-care; limited speech; walking, then swallowing, become affected; full dependenceComfort-focused care; feeding, mobility, skin, and pain management; consider palliative/hospice input

The middle stage is usually the longest and the most demanding for caregivers, and it is where most behavioural questions arise. The late stage shifts the work from cognition toward physical care and comfort.

Why stage-appropriate care matters

The single most useful thing staging does is stop two common mistakes. The first is expecting abilities the stage has already taken — asking a person in the middle stage to reason through why they can't do something, or to hold a plan across the afternoon. The second is withdrawing support the stage still rewards — over-managing an early-stage parent who can still handle much of their own day with light scaffolding.

Gitlin, Kales, and Lyketsos (2012) show that nonpharmacologic support is most effective when it is calibrated to current capacity: simplify tasks to the level the person can still succeed at, cue rather than quiz, and adjust the environment as abilities change. As the disease moves into the late stage, the same principle points toward comfort-focused care — and the American Geriatrics Society's Choosing Wisely guidance notes that in advanced dementia, careful hand-feeding is preferred over feeding tubes, which do not improve survival or comfort in this population.

Staging also helps caregivers anticipate rather than only react. Knowing which losses tend to come next lets families plan — for supervision, for home safety, for legal and financial decisions made while the person can still participate, and eventually for palliative support.

How families ask this

The question arrives in several recognisable forms:

  • "What stage of dementia is my mom in?"
  • "How do I know if my dad is in the early or middle stage?"
  • "What are the 7 stages of dementia?" (the GDS/FAST framing)
  • "How long does each stage of dementia last?"
  • "My parent still knows us — does that mean it's still early?"

Underneath each is the same practical need: what should I expect, and what kind of help actually fits right now? The research answer is that staging is a guide to care, not a verdict — and that matching support to the current stage does more good than fixing on the number.

References

  • Reisberg, B., Ferris, S. H., de Leon, M. J., & Crook, T. (1982). The Global Deterioration Scale for assessment of primary degenerative dementia. American Journal of Psychiatry, 139(9), 1136–1139.
  • Morris, J. C. (1993). The Clinical Dementia Rating (CDR): current version and scoring rules. Neurology, 43(11), 2412–2414.
  • Alzheimer's Association. (2024). 2024 Alzheimer's Disease Facts and Figures. Alzheimer's & Dementia, 20(5).
  • Gitlin, L. N., Kales, H. C., & Lyketsos, C. G. (2012). Nonpharmacologic management of behavioral symptoms in dementia. JAMA, 308(19), 2020–2029.

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Unseen Progress publishes long-form caregiver research. See the full dementia caregiver research overview for the complete framework.