Clock drawing in schizophrenia.

The Clock Drawing Test, a task sensitive to cognitive decline in neurological groups, was administered to 27 patients with schizophrenia. Clock drawings were scored for over-all global performance and the frequency of specific qualitative errors. Mean global performance scores indicated a small proportion of the sample was below the threshold typically used to identify dementia, and the patients displayed qualitative Clock Drawing deficits not fully represented in the global performance measure. Qualitative analyses indicated that size errors, graphic difficulty, and spatial planning problems were most common. Lastly, duration of illness was not related to global performance, suggesting that the latter might not reflect deterioration but the stable trajectory of impairment that may be constant through the schizophrenia illness.