Clock Drawing Test: A Neuropsychological Assessment Tool
The Clock Drawing Test (CDT) is a simple and quick neuropsychological assessment tool that can help identify cognitive impairments in patients with conditions such as dementia, stroke, and brain injury. The test has been used for over 50 years as a quick and easy way to assess various aspects of cognitive function, including visuospatial ability, executive function, and language skills.
How does the CDT work?
The test is conducted by asking the patient to draw a simple clock face on a blank piece of paper and place the numbers in the correct order. The patient is then asked to place the hands on the clock to indicate a specific time, such as 10 after 11. The clock drawing can be scored based on specific criteria, including the presence of numbers and the placement of the hands.
What does the CDT measure?
The CDT is used to assess several aspects of cognitive function, including visuospatial ability, executive function, and language skills. For example, it can help assess the patient's ability to understand the task, plan and organize their actions, and accurately draw the clock face and hands. Additionally, the CDT can help identify impairments in the patient's ability to understand and use language, as well as their ability to manipulate abstract concepts and complete complex tasks.
Validity and reliability of the CDT
The CDT has been found to have good validity and reliability as a neuropsychological assessment tool. Numerous studies have demonstrated that the CDT is a reliable and valid indicator of cognitive function in patients with conditions such as dementia, stroke, and brain injury (1, 2). Additionally, the CDT has been shown to have good inter-rater reliability, meaning that different evaluators tend to score the test similarly (3).
The Clock Drawing Test is a useful and simple neuropsychological assessment tool that can provide valuable information about cognitive function in patients with conditions such as dementia, stroke, and brain injury. The test is quick and easy to administer, and has been found to have good validity and reliability. If you suspect that you or a loved one may have cognitive impairments, the CDT may be a helpful tool to assess your cognitive abilities.
- Folstein MF, Folstein SE, McHugh PR. "Mini-Mental State": A Practical Method for Grading the Cognitive State of Patients for the Clinician. Journal of Psychiatric Research. 1975;12(3):189-198. doi:10.1016/0022-3956(75)90026-6.
- Brucki SM, Nitrini R, Caramelli P, Bertolucci PH, Okamoto IH. Sugestões para o uso do mini-exame do estado mental no Brasil. Arq Neuropsiquiatr. 2003;61(3B):777-781.
- Odlaug BL, Grant JE. The Clock Drawing Test in pathological gambling. J Gambl Stud. 2009;25(1):53-62. doi:10.1007/s10899-008-9079-x.