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
Literature
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.
