Clock Drawing Test (CDT)

The Clock Drawing Test (CDT) is a screening test sensitive to cognitive impairment and dementia. It is used as a measure of spatial dysfunction and neglect. Participating in the CDT requires verbal understanding, memory and spatially coded knowledge as well as constructive skills.

The CDT can be administered in different ways. The " free-drawn method" is when the participant is instructed to draw a clock from memory and there is no time limit. In the "pre-drawn" method, the participant is given a piece of white paper with a circle and is instructed to draw a clock. Typically, they are expected fill in the numbers and can be asked to draw the hands at a specific time (usually 10 past 11). And finally, during another method, the participant is asked to draw the hands at a specific time on a pre-drawn clock, complete with contour and numbers.

Because there are various ways to administer the CDT, there are different ways of scoring. To make it more simple, I am going to give an example of a test completed by one of my clients.

I am currently an intern at the women's prison. A few weeks ago, my supervisor (the Psychologist at the prison), was concerned about an inmate in terms of memory impairment. Throughout their session, she lost her "train of thought" numerous times and also reported short term memory loss. My supervisor asked me to work with the inmate and present an assessment that would be sensitive to what appeared to be cognitive impairment in this inmate. Both the Psychiatrist and Physician were also scheduled appointments with the inmate.

I decided to administer the CDT during the session (see photo). I gave her the "free drawn method" and instructed her to place the hands at 10 past 11. The participant placed all of the numbers in the correctly, but was not able position the hands at the specified time. The re-tracing of the hands is to be noted as it increases the score.

The method of evaluating the drawing was according to Sunderland's criterion. The results indicate a score total of 6 out of 10.