Comparison of a clock drawing test in elderly schizophrenia and Alzheimer's disease patients: A preliminary study

Jeremia Heinik*, Debbi Lahav, Dov Drummer, Zippi Vainer-Benaiah, Ruth Lin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The objective of this study was to compare between the quantitative and qualitative aspects of a clock drawing test in elderly schizophrenic and Alzheimer's disease (AD) patients. Three independent raters performed a retrospective analysis of the clock drawing item from the Cambridge Cognitive Examination (CAMCOG), in long-term open wards of a public psychiatric hospital and an outpatient psychogeriatric clinic. The study group comprised 21 elderly schizophrenic patients ('graduates') and 21 AD patients matched for gender and education, and cognitive impairment confirmed by a Folstein mini-mental state examination (MMSE) score of 18-23. The Clock Drawing Interpretation Scale (CDIS), was the measure used. Schizophrenic patients were significantly younger than AD patients (63.5 versus 81.3 years, p < 0.0001), however, similar concerning gender, education, MMSE and CAMCOG scores. CDIS scores were not correlated with age in either group. Inter-rater reliability was high (range 0.84-0.97). No significant differences between patient groups were found in mean CDIS total scores. A CDIS specific item analysis revealed that schizophrenic patients were significantly less impaired than AD patients on three out of 20 items: Number 7 (most symbols are aligned in a clockwise or a rightward direction), Number 8 (all symbols are totally within a closure figure), and Number 13 (numbers do not go beyond 12). Although schizophrenic patients and AD patients had similar total scores on the clock drawing test, they differed on specific test items related to spatial/planning deficit and preservation. Copyright (C) 2000 John Wiley and Sons, Ltd.

Original languageEnglish
Pages (from-to)638-643
Number of pages6
JournalInternational Journal of Geriatric Psychiatry
Issue number7
StatePublished - 2000
Externally publishedYes


  • Alzheimer's disease
  • Clock drawing
  • Dementia
  • Schizophrenia


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