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Why Is Drawing A Clock For Dementia

How Do You Score The Clock Draw Test

Clock drawing by patient with altered mental status versus dementia

Just as there are several forms of the clock drawing test, there are several scoring systems to determine the test results. Some are a little convoluted, too! Because the idea is just to find out if the person may need to have more in-depth testing done, the Alzheimers Association recommends using a simple method of scoring.

Per the Oregon Health and Science University, to score the results of the Clock Drawing Test for Dementia, you start by counting each word the person remembered correctly .

Next, look at three things in their clock face drawings: the clock face, the hands, and the numbers.

  • For the clock face, you are looking for whether or not all 12 numbers are included, and whether or not they are in the right place.
  • For the hands, you are looking to see if they are drawn in the right place and pointing to the correct numbers / time.
  • For the numbers, you are looking to make sure that they are legible and in order. Is the clock drawn in a fairly symmetrical way?


  • A word recall score of 0 suggests the person should be screened for dementia.
  • If there are significant differences in the clock face along with a word recall score of 1 or 2, the person should be screened.
  • If there are no differences in the clock face and a word score of 1 or 2, dementia screening is not indicated.
  • A score of 3 indicates normal cognition and no need for screening.

How To Read The Clock

It is first important to say that while the CDT is useful and widely embraced by the medical community, it is just a small step in evaluating whether someone is developing dementia. Further testing by a physician is essential before definitively saying that someone has Alzheimers disease or another dementia.

After your loved one draws the clock, you need to evaluate the image. Youll be able to tell if its right or not, but because different dementias impact different parts of the brain, several aspects of the drawing are revealing:

The Size of the Clock. Patients with Parkinsons disease dementia and Huntingtons disease, a rarer dementia that can develop in a persons 30s and 40s, are prone to draw a smaller clock , while people with Alzheimers disease tend to draw bigger clocks. This is because size awareness is affected differently depending on which illness is present.

Fixating on Time. If the person being tested is focused mostly on the time aspectgetting the hands pointed the right way so the clock is correctto the detriment of the rest of the clock, this is more common in Alzheimers disease and Parkinsons disease dementia than with other dementias.

Graphical Errors. If the clock looks essentially correct, but is messy , this is more common in Huntingtons disease and vascular dementia than Alzheimers disease.

See images of other individuals Clock-Drawing Tests results here.

Did You Know?

How To Administer The Clock Drawing Test

How to Administer the Clock Drawing Test
Step 1 Find a table and chair in a room that is familiar or free of distractions. Sit your loved one down at the table and provide a single sheet of paper and a writing utensil. It is best to provide a pencil with an eraser as this may help to lessen any frustration for the test taker. Note that its also OK to pre-draw a 10-inch circle for your loved one, rather than starting with a blank page.
Step 2 Say Draw a clock that shows the time as 10 minutes after 11. If further prompting is needed, its OK to be more specific: Draw a circle to represent the face of the clock, then add the numbers, and then the hands. The test will still work this way.
Step 3 Allow as much time as needed to complete the task. Rarely will the task take more than 10 minutes. It is suggested that one might put themselves out of visual range of the test taker in order to discourage questions. If questions are asked, either refrain from answering or simply say just do as you think best.
Step 4 Assess the clock, looking for abnormalities. If your loved one is distracted, or refuses to draw after having agreed to do so, you might consider these actions as a fail and seek further assessment from a doctor. More on how to assess the Clock-Drawing Test results below.

Provide the Circle?

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Continue Learning About Dementia Diagnosis

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.

How To See Signs

Examples of clock drawings produced by people diagnosed with dementia ...

I am hoping that this post is generating some thought about how your parents brains are aging. The early signs are so subtle, we tend to overlook their importance until it becomes of epic proportion. Getting your parent to a doctor for memory concerns is a difficult task and one that requires love, compassion and a knack for negotiation. How do you begin this task?

  • Spend more time with your parent. If you live a distance, make a decision to call them more. Listen to them. Can your mother remember all the words shes trying say? Can your father finish a thought in a sentence? Has dad become quieter in larger family gatherings? Does mom repeat herself and not realize this? Has your dad switched dates and times more than once?
  • Make notes of these observations to collect data that you can speak to when you approach your parent
  • If you have siblings, share with them your concerns and see if they have observed similar changes
  • Generate a plan to gently approach your parent with your concerns sharing the data you have collected
  • Ask your parents permission to bring them to their PCP for a check-up and while there, ask if they will allow the PCP to include you in the conversation.
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    Patients With Amci Or Edat

    Patients with aMCI or eDAT were recruited from the Memory Clinic of the Department of Psychiatry and Psychotherapy at the University Hospital of Tübingen. They underwent physical, neurological, neuropsychological and psychiatric examinations as well as brain imaging. Routine laboratory tests included Lues serology and analysis of vitamin B12, folic acid and thyroid-stimulating hormone levels.

    The diagnostic criteria for eDAT were defined according to the National Institute of Neurological and Communicative Disorders and Stroke Alzheimers Disease and Related Disorders Association . All of these patients had a score of 4 on the Global Deterioration Scale .

    The diagnosis of aMCI was defined according to the Mayo criteria , which include the presence of a memory complaint , objectively impaired memory function, intact activities of daily living and the absence of dementia.

    What Is The Alzheimers Clock

    The Alzheimers Clock-Drawing Test is a fast, simple way of spotting warning signs for Alzheimers disease and other related dementias that can be administered by non-professionals in the comfort of ones home. While a true diagnosis of Alzheimers or dementia obviously requires more than a few minutes of drawing with a pencil and paper, the CDT is useful for identifying issues in thinking ability that might indicate the presence of these illnesses.

    The CDT also provides a powerful visual for families to see that something is wrong with their loved one. Although the test may not seem scientific, it is backed by science and has contributed to earlier diagnoses and improved quality of life for persons with dementia.

    Its important to remember that no true diagnosis can be made without further tests from a doctor. If the clock is drawn incorrectly , that is not cause for despair. It simply means you need to make a doctors appointment so your loved one can be evaluated by an expert.

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    Screening Value Of The Clock Drawing Task In Patients With Amci Showing Normal Ccdt Score And Healthy Controls

    In the aMCI group with normal cCDT scores and HC time-in-air discriminated best with an accuracy of 79.5% at a cut-off of 36468 ms showing a sensitivity of 80.8% and a specificity of 77.8% .

    Figure 3. ROC curve analysis for discriminating patients with aMCI with unimpaired cCDT scores from HC individuals using time-in-air, time-on-surface, or total-time.

    Table 4. Diagnostic value of time-in-air, time-on-surface and total-time in differentiating patients with aMCI and HC individuals with unimpaired cCDT scores .

    An accuracy of 63.6% was found when time-on-surface was used to discriminate between aMCI patients with normal cCDT score and HCs at a cut-point of 15803 ms with sensitivity of 65.4% and specificity of 61.1% .

    When total-time was used to discriminate between the aMCI group with normal CDT scores and healthy individuals, an accuracy of 75.0% was found at 54624 ms with sensitivity of 76.9% and specificity of 72.2% .

    In order to improve the discrimination of aMCI with normal cCDT from HC forward stepwise logistic regression model combing time-in-air, time-on-surface and total-time revealed significant Odds Ratio for time-in-air as the best predictor variable . The combination with time-on-surface , and/or total-time did not improve discriminative power and were excluded from the model assumptions.

    Figure 4. Unimpaired clock drawing performed by a HC individual. On-surface curves are displayed in deep black color, in-air movements are displayed in red color.

    The Clock Drawing Test

    Clock drawing test dementia

    Why a clock?? I have read several articles on understanding the role of drawing the clock in evaluating a dementia diagnosis. I will trim the treetops for you. The CDT is an excellent brief test to screen for dementia as the accurate drawing of the clock requires several frontotemporal to work congruently. This test can be administered during a visit to the primary care physician . New studies on the CDT are suggesting that how the clock is drawn and what may have been forgotten in the drawing could be indicators of the type of dementia that is unfolding.

    What was interesting for me to observe with Mom was that each time she was asked to draw the clock she struggled with the same concept. Mom could draw the circle and slowly wrote the numbers around the face of the clock in the correct order, with the exception of one number. She consistently forgot the 11th hour. This made completing the exercise she was asked to do impossible as she was asked to draw 10 minutes past 11. There was no 11 on her clock. She actually giggled when it was pointed out to her each time. Damn her pea brain she would say.

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    Losing Track Of Time Why Do People With Dementia Struggle To Tell The Time

    When someone has dementia the parts of their brain used for telling the time begin to deteriorate and eventually stop functioning.

    When they look at a clock face they might not be able to understand what the hands are pointing at, and they may easily lose track of what time of day it is often confusing night with day, or even what month or season it is.

    Losing sense of time inevitably leads to confusion, and this in turn can lead to anxiety, challenging behaviour, anger and even loss of self.

    What are the problems associated with losing track of time?

    The Clock Test is often used by Doctors to determine early signs of dementia. They will draw a circle and ask the patient to add the numbers as the face of the clock, and then draw the hands as a particular time.

    Generally a person with dementia, especially Alzheimers, will be unable to do this. The part of the brain that enables this kind of reasoning is damaged. They will no longer be able to read the face of a clock or understand the positioning of the hands, and therefore will not be able to tell what time it is.

    Memory problems also make it likely that they will forget what day it is, or even what month or season, leading to confusion about what they should be doing, where they need to be, or even what they should wear.

    They might end up ringing you up constantly to ask what time it is, or worse still, they might end up believing you have abandoned them and are never coming back, or are up to something.

    Identifying Dementia Subtypes With The Clock Drawing Test

    The clock drawing test is useful for diagnosing dementia, but can it differentiate Alzheimer disease from other forms of dementia?


    The clock drawing test is useful for diagnosing dementia, but can it differentiate Alzheimer disease from other forms of dementia? Because a variety of skills are needed to successfully complete the CDT, researchers have reasoned that examination of the pattern of errors made by an individual patient may identify dementia subtype. The results of studies seeking to confirm this, however, have been conflicting. Researchers from the Sunnybrook Health Sciences Centre in Toronto, Canada, conducted a literature review to get more clarity on the issue.1

    Databases searched included MEDLINE, PsycINFO, and Embase, and search terms included clock drawing or CLOX plus dementia, Parkinsons disease, Alzheimers disease, dementia with Lewy bodies , or vascular dementia. The analysis included any study published in English that used the CDT to compare patients with AD with patients with other dementias. An additional inclusion criterion was that diagnoses were based on clearly defined criteria and/or autopsy findings.

    ]Of 866 potentially relevant references, 20 studies met inclusion criteria. Of these, CDT scores of patients with AD were compared with those of patients with vascular dementia in 11 studies, with Parkinsons disease dementia in 6 studies, DLB in 4 studies, and frontotemporal dementia in 3 studies .

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    What Does It Mean If You Fail The Clock Drawing Test

    If you have performed the clock drawing test on a friend or family member, you may become concerned if they draw an abnormal clock or different times than you request.

    While this may indicate that your loved one is suffering from dementia or Alzheimers, this isnt always the case. This is because the clock test only tests for cognitive deficits, not a particular disease.

    To perform well on the clock test, your loved one must first understand your verbal instructions so they know what you want them to do. They also must have spatial knowledge, visual memory, and the ability to think abstractly. If they are missing even one of these things, they will be unable to perform well on the clock test.

    A failed clock test could indicate Parkinsons Disease, Huntingtons Disease, Alzheimers disease, vascular dementia, frontotemporal dementia, or dementia with Lewy bodies, depending on which aspects of the clock the individual is able to complete.

    This is why you shouldnt treat the failed clock test as the absolute answer as to whether or not your loved one has dementia. Instead, you should think of a failed clock test as a sign that your loved one needs some professional help.

    Neglect And Spatial Deficits

    Dementia Clock Drawing at GetDrawings

    In individuals with spatial deficits, there may be crowding of numbers and/or obvious impairments in the layout of the clock. The usual striking example is when a clock drawing has all the numbers on one half of the clock but not the other half. In this case, the clock-drawing test can be used to reveal neglect, but is not diagnostic.

    Neglect can commonly be seen in individuals with stroke. It is most common after lesions of right parietal lobe or right frontal lobe. Other areas, such as the thalamus and the basal ganglia, can also be involved. Patients with right-sided lesions typically neglect the left hemispace. Neglect can be further divided into motor and sensory components, extinction, anosognosia , and anosodiaphoria .

    In the example showing hemineglect, the absence of numbers on the left suggests that there is a right parietal cortical lesion. In this case, the individual would benefit from a comprehensive neurological examination.

    Fig. 4

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    Digital Clock Drawing Test

    The clock drawing test has been used for several decades as a simple and effective means of diagnosing disruptions to spatial orientation and dementias. Scientists at the Pattern Recognition Lab at the Department of Computer Science at FAU fed AI neural networks with data from 2500 tests to teach them how to assess these results independently. The research findings have been published in the journal Scientific Reports. The same group also plan to launch open source software that could make diagnosing dementia much easier for medical and neuropsychological specialists.

    What Does Research Say About The Clock Test

    Compared to the Mini-Mental State Examination , the clock drawing test is thought to have less educational bias and is better able to detect cognitive decline due to Alzheimers disease and other dementias. The MMSE is known to have some issues with the educational level of the individuals taking the test , as well as not being as sensitive to milder cognitive changes and is primarily sensitive to detecting Alzheimers than other dementias. The clock drawing test has also been advocated over the MMSE as an office screening test for dementia in community clinics and in acute hospital settings. It requires less time to administer and to score. Furthermore, the clock drawing test is suitable for non-English speaking populations, whereas the MMSE does have some language bias.

    A 2010 study from researchers at the Alzheimers Disease Center at Boston University School of Medicine looked at interrater reliability and diagnostic accuracy of the Clock Drawing Test. They found it had excellent interrater reliability, sensitivity , and specificity for predicting a consensus diagnosis and excellent interrater reliability and sensitivity for differentiating participants with mild Alzheimers Disease from the control participants. The researchers found that while the clock drawing test may be a good screening instrument for Alzheimers disease although it is not recommended to use as a stand-alone screening, it may not be a sensitive instrument for screening mild cognitive impairment.

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