Clock Drawing Test (CDT)

In a primary care setting, one common reason that patients are referred to behavioral health is for complaints of memory loss. There are a whole host of conditions that can cause a patient to present complaining of memory problems ranging from lack of sleep to dementia. In the primary care setting, full neuropsychological assessment is not an option, and yet primary care providers (PCPs) need a way to determine whether a referral to neurology is warranted or if it is more appropriate to explore other avenues first.

There are a number of brief cognitive screeners that can be used in the primary care setting. The Clock Drawing Test (CDT) is an evidence-based screening tool that is sensitive to neurologic conditions independent of mood or anxiety symptoms . It is a useful frontline screener  because it is quick, sensitive, and specific . It may also be an appropriate tool for monitoring patients clinical progress over time .

The CDT is simple to administer, but there are any number of scoring methods. A study in Denmark compared five different scoring methods and found that predictive values were nearly identical regardless of the scoring method use. They suggested clinicians use the simplest scoring method which uses a pass/fail paradigm in which the “CDT [is considered] normal if all numbers were present in the correct sequence and position, and the hands readably displayed the requested time” .

After I administer the CDT with the patient in the exam room, I provide brief feedback to the patient and the provider and then document the results the EHR. In the score field I documents either a 0 or a 1. In the interpretation field I indicate that the score is:

1 = Normal
0 = Further evaluation indicated. Refer to neurology

And in the comments field I enter:

Score and interpretation based on Borson, Scanlan, Brush, et al., (2000). The CDT is sensitive to neurologic conditions independent of mood or anxiety symptoms (Schillerstrom, Regwan & Harlan, 2010).

What has been you experience with brief screening of memory changes? Feel free to share in the comments below.




Cite this article as:
Robert Allred, "Clock Drawing Test (CDT)," in Robert P. Allred, PhD, March 31, 2017,


APA 6th:
Allred, R.P. (March 31, 2017). Clock Drawing Test (CDT) [Weblog post]. Robert P. Allred, PhD. Retrieved December 15, 2017 from

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