The Clinical Dementia Rating or CDR is a numeric scale used to quantify the severity of symptoms of

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

(i.e. its 'stage').

Scale

Using a structured-interview protocol developed by Charles Hughes, Leonard Berg, John C. Morris and other colleagues at

Washington University School of Medicine Washington University School of Medicine (WUSM) is the medical school of Washington University in St. Louis in St. Louis, Missouri. Founded in 1891, the School of Medicine has 1,260 students, 604 of which are pursuing a medical degree with ...

, a qualified health professional assesses a patient's cognitive and functional performance in six areas:

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered ...

orientation Orientation may refer to: Positioning in physical space * Map orientation, the relationship between directions on a map and compass directions * Orientation (housing), the position of a building with respect to the sun, a concept in building de ...

, judgment & problem solving, community affairs, home & hobbies, and personal care. Scores in each of these are combined to obtain a composite score ranging from 0 through 3. Clinical Dementia Rating Assignment Qualitative equivalences are as follows:NACC Clinical Dementia Rating CDR is credited with being able to discern very mild impairments, but its weaknesses include the amount of time it takes to administer, its ultimate reliance on subjective assessment, and relative inability to capture changes over time.

Validity

While the assessment is ultimately subjective in nature, recent studies have suggested a very high interrater reliability. Thus the CDR is a reliable and valid tool for assessing and staging dementia.

Importance

With increasing clinical focus on dementia, there is likewise increasing interested in pharmacology in the development of drugs to halt, or slow the progression of dementia-related illness such as Alzheimer's Disease. Therefore, early and accurate diagnosis of dementia and staging can be essential to proper clinical care. Without the ability to reliably assess dementia across the board, the misuse of anti-dementia compounds could have negative consequences, such as patients receiving the wrong medication, or not receiving treatment in the early stages of dementia when it is most needed.

References

{{Neuropsychology tests Cognitive disorders Neuropsychological tests Memory tests Cognitive impairment and dementia screening and assessment tools