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Clinical Dementia Rating (CDR)
CDR: Staging tool requiring structured clinician interview of patient and informant. Memory is the primary domain. Assess pre-morbid baseline.
Rate each domain
Memory
Primary Domain
Orientation
Judgment & Problem Solving
Community Affairs
Home & Hobbies
Personal Care
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Staging dementia severity for clinical management and care planning.
Research and clinical trials — CDR Sum of Boxes (CDR-SB) is a primary outcome in Alzheimer's disease trials.
Longitudinal monitoring of dementia progression over months to years.
Hospice and advanced care planning — CDR 3 (severe) supports 6-month hospice eligibility.
Staging vs. Screening
The CDR is a staging tool, not a screening tool. It requires structured clinician interview of both the patient and a knowledgeable informant and takes 20–40 minutes. Use Mini-Cog, MoCA, or AD8 for initial screening; use CDR when diagnosis is established and staging is needed.
Section 2
Formula & Logic
Global CDR Score
CDR 0: No dementia
CDR 0.5: Questionable / Very Mild Dementia (MCI range)
CDR 1: Mild Dementia
CDR 2: Moderate Dementia
CDR 3: Severe Dementia
CDR-SB (Sum of Boxes): 0–18 — sum of all 6 domain ratings
CDR-SB is more sensitive to longitudinal change than global CDR
6 Assessed Domains
Memory
Primary domain; weighted most heavily in global score
Orientation
Time, place, person orientation
Judgment & Problem Solving
Financial, civic, community affairs
Community Affairs
Independence in job, shopping, volunteering
Home & Hobbies
Function at home, intellectual interests
Personal Care
Hygiene, dressing, eating — without prompting
Section 3
Pearls/Pitfalls
Memory Domain Rules
Memory is the primary domain in CDR scoring. If memory is rated 0 or 0.5, the global CDR cannot exceed 1. The complex scoring algorithm (not a simple average) must be applied correctly — use a validated CDR scoring algorithm or the CDR-SB to avoid errors.
Full-time supervision. Medication management. BPSD management. Residential care planning.
CDR 3 (Severe)
Palliative approach. Advance care planning. Hospice eligibility consideration.
Section 5
Evidence Appraisal
Primary Reference
A new clinical scale for the staging of dementia.
Hughes CP et al. • Br J Psychiatry.. 1982;140:566–572. Original derivation; validated against neuropathological diagnosis of Alzheimer's disease.
Section 6
Origins
Washington University Alzheimer's Disease Research Center
Developed at Washington University in St. Louis by Charles Hughes and Leonard Berg in 1982. The CDR was designed as a structured clinician-rated staging tool that integrates patient performance with informant-reported functional change. The CDR-SB (Sum of Boxes) — a quantitative continuous variant — was later validated as the primary endpoint in multiple Alzheimer's disease disease-modifying trials including the lecanemab and donanemab pivotal studies.
Last Comprehensive Review: 2026
Guidelines & Evidence
Clinical Details
Section 1
When to Use
Clinical Utility
Staging the severity of cognitive impairment in dementia (primarily Alzheimer's disease).
Differentiating between normal aging, Mild Cognitive Impairment (MCI), and various stages of dementia.
Monitoring global functional and cognitive decline over time.
Clinical research standard for characterizing patient populations in dementia trials.
Section 2
Formula & Logic
The Six Cognitive Domains
Memory (M): The primary domain for staging.
Orientation (O): Awareness of time and place.
Judgment & Problem Solving (JPS): Handling complex business or social situations.
Community Affairs (CA): Functioning at work or in social groups.
Home & Hobbies (HH): Maintenance of household tasks and interests.
Personal Care (PC): Basic ADLs like dressing, hygiene, and grooming.
Global CDR Staging
CDR 0
No Impairment
CDR 0.5
Very Mild / Questionable (MCI)
CDR 1
Mild Dementia
CDR 2
Moderate Dementia
CDR 3
Severe Dementia
Section 3
Pearls/Pitfalls
Memory as the Keystone
The Global CDR is heavily weighted by the Memory score. If Memory is 0, the overall score is usually 0 unless significant impairment exists in multiple other domains.
Diagnostic Pearls
Assessment requires information from both the patient and a reliable collateral historian (informant).
CDR 0.5 is often used as the clinical threshold for Mild Cognitive Impairment (MCI).
Personal Care (PC) is usually the last domain to decline; severe impairment here typically indicates CDR 3.
Section 4
Next Steps
Care Planning by Stage
01
CDR 0–0.5: Focus on secondary prevention (CV health, exercise) and baseline advanced directives.
CDR 2: Intensify home supervision; consider adult day care; Memantine addition.
04
CDR 3: 24-hour care or skilled nursing facility transition; focus on comfort and palliative measures.
Section 5
Evidence Appraisal
Primary Reference
The Clinical Dementia Rating (CDR): current version and scoring rules
Morris JC • Neurology. 1993;Vol 43, Issue 11. pp. 2412-2414. The definitive publication for the widely accepted scoring algorithm.
Section 6
Origins
Washington University
Developed at Washington University in St. Louis in 1979 as part of the Memory and Aging Project. It was designed to provide a global staging of impairment rather than just a cognitive test score.
