The Clinical Dementia Rating (CDR)
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 provided "Full" and "Refresher" training on this site is technically referred to as the Brief Training & Reliability Protocol (BTRP) as it is a subset of the complete CDR training that takes place in-person at the Knight ADRC.
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
A sample CDR Table is available by clicking HERE.
The CDR instrument and this training site were developed, in large part, through funding support from the following National Institute on Aging grants:
- Alzheimer's Disease Center Grant (AG05681)
- Healthy Aging & Senile Dementia (AG03991)
- Alzheimer's Disease Cooperative Study (AG10483)
A brief list of literature related to the CDR can be found at the links below.
Interobserver Disagreements on Clinical Dementia Rating Assessment: Interpretation and Implications for Training. Rochelle E. Tractenberg, Kimberly Schafer, John C. Morris. Alzheimer Disease and Associated Disorders 2001; 15: 155-161. Abstract Link
Morris JC. The Clinical Dementia Rating (CDR): Current version and scoring rules. Neurology 1993; 43:2412-2414. Abstract Link
Hughes CP, Berg L, Danziger WL, Coben, LA, Martin, RL. A new clinical scale for the staging of dementia. Br J Psychiatry 1982; 140:566-572. Abstract Link
Berg L. Clinical Dementia Rating (CDR). Psychopharmacol Bull 1988; 24:637-639. Abstract Link
Morris JC, Berg L, Coben LA, Rubin EH, Deuel R, Wittenborn R,et.al Clinical Dementia Rating. In Treating "Alzheimer's and other Dementias". M. Bergener and S. Finkel (eds) 1995, 338-346. Morris JC, Ernesto C, Schafer K, et. al. Clinical Dementia Rating training and reliability in multicenter studies: The Alzheimer's Disease Cooperative Study experience. Neurology 1997; 48:1508-1510. Abstract Link
Rockwood K,Strang D, MacKnight C, et. al. Interrater reliability of the Clinical Dementia Rating in a multicenter trial. JAGS 2000; 48:558-559. Abstract Link
Morris JC, McKeel DW Jr, Fulling K, Torack RM, Berg L. Validation of clinical diagnostic criteria for Alzheimer's disease. Ann Neurol 1988; 24:17-22. Abstract Link
Burke WJ, Miller JP, Rubin EH, et. al. Reliability of the Washington University Clinical Dementia Rating. Arch Neurol 1988; 45:31-32. Abstract Link
Berg L. Clinical Dementia Rating [correspondence]. Br J Psychiatry 1984; 145:339. Abstract Link
Berg L, Miller JP, Storandt M, et. al. Mild senile dementia of the Alzheimer type: 2. Longitudinal assessment. Ann Neurol 1988; 23:477-484. Abstract Link
McCulla MM, Coats M, Van Fleet N, Duchek J, Grant E, Morris JC. Reliability of clinical nurse specialists in the staging of dementia. Arch Neurol 1989; 46:1210-1211. Abstract Link
Use all information available and make the best judgment. Score each category (M, O, JPS, CA, HH, PC) as independently as possible. Mark in only one box, for each category, rating impairment as decline from the person’s usual level due to cognitive loss alone, not impairment due to other factors, such as physical handicap or depression. Occasionally the evidence is ambiguous and the clinician’s best judgment is that a category could be rated in either one of two adjacent boxes, such as mild (1) or moderate (2) impairment. In that situation the standard procedure is to check the box of greater impairment.
Aphasia is taken into account by assessing both language and non-language function in each cognitive category. If aphasia is present to a greater degree than the general dementia, the subject is rated according to the general dementia. Supply evidence of non-language cognitive function.
The global CDR is derived from the scores in each of the six categories ("box scores") as follows. Memory (M) is considered the primary category and all others are secondary. CDR = M if at least three secondary categories are given the same score as memory. Whenever three or more secondary categories are given a score greater or less than the memory score, CDR = score of majority of secondary categories on whichever side of M has the greater number of secondary categories. When three secondary categories are scored on one side of M and two secondary categories are scored on the other side of M, CDR=M.
When M = 0.5, CDR = 1 if at least three of the other categories are scored one or greater. If M = 0.5, CDR cannot be 0; it can only be 0.5 or 1. If M = 0, CDR = 0 unless there is impairment (0.5 or greater) in two or more secondary categories, in which case CDR = 0.5.
Although applicable to most Alzheimer's disease situations, these rules do not cover all possible scoring combinations. Unusual circumstances occur occasionally in Alzheimer's disease and may be expected in non-Alzheimer dementia as well are scored as follows:
- With ties in the secondary categories on one side of M, choose the tied scores closest to M for CDR (e.g., M and another secondary category = 3, two secondary categories = 2, and two secondary categories = 1; CDR = 2).
- When only one or two secondary categories are given the same score as M, CDR = M as long as no more than two secondary categories are on either side of M.
- When M = 1 or greater, CDR cannot be 0; in this circumstance, CDR = 0.5 when the majority of secondary categories are 0.
Morris, J.C. (1993). The clinical dementia rating (CDR): Current version and scoring rules. Neurology, 43(11), 2412-2414.
To view these rules as a PDF, click the image below.
Copyright & Licensing
The Washington University The Charles F. and Joanne Knight Alzheimer's Disease Research Center (Knight ADRC) holds the United States Copyright for the Clinical Dementia Rating (CDR) and associated training materials. An important part of the Knight 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.
If you would like to license the CDR (non-profit and for-profit), please visit https://otm.wustl.edu/for-industry/tools/#CDR. Click the "Read More" option and select the responses that apply to your intended use of the CDR. Once completed, send your agreement to the contracts group at MTA@DOM.wustl.edu. If you have any questions regarding the agreement, please email the contracts group.
Prospective users of the CDR should be trained to administer the semi-structured interview and use the Scoring Table in a valid, reliable manner. We prefer to provide such training through live, in-person sessions either at our 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.
Public Training (Free Access)
There is no a charge option available to individual trainees wishing to be CDR trained online. Only English subtitles are provided for this free training option. See Private Training below concerning the availability of other subtitle languages. The Washington University Knight ADRC reserves the right to bar access to prospective trainees who do not provide a bona fide reason for receiving CDR training. Minimal technical support is provided. Access to a CDR expert for training questions is not provided. It is expected that trainees who take the online training are already familiar with the CDR. A certificate is issued for those who pass the training. A limited set of remedial modules is provided for trainees that fail their initial training modules.
Private Training (Group or Corporate Access, Fee Based)
Group or corporate users of the training system should contact Ronald Hawley concerning training access options and applicable fees.
This fee-based training option provides subtitles for all training videos in English, French, Spanish, Japanese and Korean (as of 2/17/2017). More languages are currently in development. This option also provides access, if needed, to a CDR expert at the Knight ADRC should concerns or questions arise during training. Additionally, technical support is provided. If a streaming problem cannot be solved, a set of training DVDs will be sent via FedEx at no additional charge. A limited set of remedial modules is provided for trainees that fail their initial training modules. Finally, not only will a trainee receive a certificate upon sucessful completion of the training, individuals within the trial's organizing institution can also be designated to receive the same certificate--eliminating the need for a trainee to forward his/her certificate.
The CDR On-line Training System utilizes video segments of real patient interviews. All interview participants provided informed consent for their images to be shown for appropriate educational purposes. Apart from the visual appearance of each interviewee, there is no other identifying information in these interview segments. Nevertheless, we ask that approved trainees (1) respect the confidentiality of those they observe and (2) refrain from discussing interview content with others. Browsers of the CDR On-line Training System may view certain video segments but with the faces of interviewees blocked out.
The translations available below are made possible through the generous efforts of MAPI Research (translation certificate), TransPerfect (translation certificate) and Corporate Translations (translation certificate). Each translation includes the CDR semi-structured interview in worksheet form and the CDR scoring table. The scoring rules for global CDR determination are available in English only (Click here to view). Please consider using our online scoring algorithm to ensure an accurate final CDR rating.
The materials provided below are intended for clinical and research use. We strongly recommend individuals using CDR materials apply for training via our Online CDR Training System. All files below are in Adobe Acrobat PDF format.
You can click HERE to use the online CDR scoring algorithm. The linked page allows the user to input CDR box scores and submit them to a SAS computer program which returns the global CDR.
Online Certification Training
Free training in the CDR is provided by clicking HERE. Once your application has been submitted, you'll immediately be able to begin training.
Sample CDR Training
Browsing the CDR allows those not interested in formal training to view three sample CDR training videos. These videos have been altered to remove the individuals' faces to protect their identity. If after viewing the samples videos you wish to take the formal training, a link will be provided to do so. Begin by clicking HERE.
Click HERE to view our streaming requirements page.
Lost your place during training?
If you've lost your place during training, click HERE to submit a request for a link to resume.
Pick from the available studies below to begin your training. You may need to contact your study coordinator for the password to access the study's application.
Click HERE to view our streaming requirements page.
Lost your place while taking training?
If you failed to bookmark (also referred to as Add to Favorites) the module you are on when you stopped training, or had a computer glitch that has prevented you from picking up where you left off, you can contact the webmaster to receive the direct link to continue training. Emails to the webmaster are generally handled within an hour or less during the business hours of 8:30am and 4:00pm Central Time (excluding holidays and weekends).
Please include the following in your email to the webmaster:
- Full name you used when filling out the CDR Training Application
- Email address you used on your CDR Application
- Email address you would prefer to be contacted at if it differs from the address in item 2 above.
CLICK TO CONTACT KNIGHT ADRC WEBMASTER or send an email to: firstname.lastname@example.org
How to bookmark web pages:
- Internet Explorer, Chrome, Firefox, Safari and Opera Instructions
- For situations that deviate from the instructions provided at the link above, consult your IT support.