Clock drawing, clock reading, clock setting, and judgment of clock faces in elderly people with dementia and depression.

Objectives: To assess patient performance on different clock tasks.

Design: Group comparisons.

Setting: A hospital-based memory clinic; inpatient and outpatient memory clinic.

Participants: Patients with dementia (n=30), patients with depression (n=30), and healthy controls (n=30).

Measurements: General neuropsychological tests, clock drawing tests, and three additional clock tasks: clock reading, clock setting, and judgment of clock faces (each comprising 12 items).

Results: Demented patients differed significantly from the control and depression groups on all clock tasks; controls and depressed patients differed only in the clock-setting task. A comparison between tasks showed that clock setting was the most difficult, which differentiated best between diagnostic groups. Groups differed not only in overall performance scores, but also in error characteristics.

Conclusion: Overall, study results indicate that clock setting is a sensitive task that may prove to be a valuable tool when screening for dementia.