The following is an excerpt from the Washington University in St. Louis Alzheimer's Disease Research Center's website: www.adrc.wustl.edu 
The CDR is a 5-point scale used to characterize six domains of cognitive and functional performance applicable to Alzheimer disease and related dementias: Memory, Orientation, Judgment & Problem Solving, Community Affairs, Home & Hobbies, and Personal Care. The necessary information to make each rating is obtained through a semi-structured interview of the patient and a reliable informant or collateral source (e.g., family member).
The CDR table provides descriptive anchors that guide the clinician in making appropriate ratings based on interview data and clinical judgment. In addition to ratings for each domain, an overall CDR score may be calculated through the use of an algorithm. This score is useful for characterizing and tracking a patient's level of impairment/dementia:
0 = Normal
0.5 = Very Mild Dementia
1 = Mild Dementia
2 = Moderate Dementia
3 = Severe Dementia
COPYRIGHT & DISSEMINATION
The Washington University Alzheimer's Disease Research Center (ADRC) holds the United States Copyright for the Clinical Dementia Rating (CDR) and associated training materials. An important part of the Washington University ADRC's educational mission is to ensure that the CDR is widely and readily available for use by professionals in clinical and research settings. Protecting the integrity of the instrument and ensuring appropriate utilization are equally important priorities.
The CDR scoring table and rules were published in the journal NEUROLOGY, 1993; 43:2412-2414 (author Morris, JC). Reprinting of this table in a publication requires permission from the publisher - Lippincott, Wilkins & Williams.
The CDR may be used for clinical care and non-commercial research purposes without formal permission of the Washington University ADRC. Individuals or corporations intending to use the CDR for clinical trial or other for-profit purposes must obtain prior permission.
Prospective users of the CDR should be trained to administer the semi-structured interview and use the Scoring Table in a valid, reliable manner. The Washington University ADRC prefers to provide such training through live, in-person sessions either at their offices or at pre-arranged remote events. Such live training is often not possible, however. The CDR On-line Training System was developed with two purposes in mind: (1) as a supplement to in-person training and (2) as a stand-alone training option for individuals and groups that cannot participate in an in-person session. In-person training is important to ensure valid administration, whereas the on-line system helps to ensure reliability in scoring.