The Dementia Rating Scale helps assess and track the mental functions of people suffering with a brain dysfunction that is causing cognitive impairment.
The Dementia Rating Scale
Written by Steven Mattis, Christopher Leitten and Paul Jurica, the rating scale for dementia, known as the DRS-2, replaced the original rating scale for dementia called the DRS, or the MDRS (Mattis Dementia Rating Scale).
Published by Psychological Assessment Resources, the DRS-2 is administered on an individual basis to patients aged fifty-five to eighty-nine. The rating scale consists of thirty-six tasks with thirty-two stimulus cards and takes fifteen to thirty minutes to administer.
The DRS-2 assesses individuals in five areas resulting in five sub-scale scores. These scores are used to determine the overall score and level of cognitive functioning ability. The five areas include:
- Attention - measured using eight items
- Construction - measured using six items
- Conceptualization - measured using six items
- Initiation/Preservation - measured using eleven items
- Memory - measured using five items
This rating scale has been found to be especially useful in the initial assessment of, tracking the progression of and measuring the changes of cognitive functions over time. Widely used to measure the cognitive abilities at the lower level ability of the spectrum, the DRS-2 is especially useful for assessing and tracking certain types of dementia including:
- Alzheimer's type dementia
- Age related dementia or Vascular dementia
- Huntington's disease
- Parkinson's disease
- Down's syndrome
- Mental retardation
Alternate Version of the DRS-2
Websites that offer the DRS-2 to professionals, also often provide an alternate form of the assessment. The purpose of the alternate version is to reduce the possibility of practice effects, which often occur with multiple assessment administrations.
DRS-2 and Alternate Form Components
Included in the DRS-2 kit are:
- A professional manual
- Thirty-two stimulus cards
- Fifty scoring booklets
- Fifty profile forms
Included in the alternate version of the DSR-2 kit are:
- A supplement to the manual
- Alternate form stimulus cards
- Fifty alternate form scoring booklets
- Fifty profile forms
Clinical Dementia Rating
The Clinical Dementia Rating, known as the CDRS, was developed in 1979 at the Washington University School of Medicine in St. Louis, Missouri, by John C. Morris as part of the Memory and Aging Project. The rating scale measures the stages and severity of several forms of dementia, although it was originally developed to measure dementia of the Alzheimer's type.
The CDRS is a five-point rating system:
- A score of 0 indicates no cognitive impairment or dementia
- A score of 0.5 indicates questionable or very mild cognitive impairment or dementia
- A score of 1 indicates mild cognitive impairment or dementia
- A score of 2 indicates moderate cognitive impairment or dementia
- A score of 3 indicates severe cognitive impairment or dementia
Scores are determined based on information gathered in an interview that is strictly structured. The person administering the interview must follow strict guidelines and rules in administering and scoring the CDRS. The six areas, or cognitive domains, covered in the interview are:
- Community affairs
- Homes and hobbies
- Personal care
In most cases, the severity of the impairment differs from one cognitive domain to another since dementia does not progress uniformly in the brain. For example, an individual may score a 2 in memory, a 1 in orientation and community affairs and a 0.5 in the remaining three cognitive domain areas. To accurately score the CDRS, the administrator uses the individual box scores of each area to derive a global CDR score following the strict published scoring rules.
Additional Scales Used to Rate Dementia
The following are several additional scales and assessments used in rating the stages and severity of various forms of dementia:
- Alzheimer's Disease Assessment Scale
- Blessed Dementia Scale
- Standardized Alzheimer's Disease Assessment Scale
- Mini-Mental State Examination
- Wechsler Adult Intelligence Scale
Both the DRS-2 and the CDRS are effective tools in evaluating the cognitive functions of individuals aged fifty-five or older that have various forms of dementia.