OBJECTIVES: To compare the Clock Drawing Test (CDT) performance of Filipino patients with schizophrenia and normal subjects in detecting cognitive impairment and to determine the correlation of symptom severity using Brief Psychiatric Rating Scale (BPRS) and Positive and Negative Syndrome Scale (PANSS) with the CDT performance among schizophrenic subjects.
METHODOLOGY: A descriptive cross-sectional study using convenient sampling. Stable and compliant schizophrenic subjects were recruited at the psychiatry OPD of our institution from July to November 2004. Normal subjects were recruited from the community who were age,sex, and education matched. CDT and MMSE were administered to all the subjects and the scores of the two groups were compared using the two-tailed Student t-test. Symptom severity using BPRS and PANSS were correlated with CDT and Mini Mental Status Exam (MMSE) in schizophrenic subjects using the Pearson;s correlation coefficient.
RESULTS: A total of 66 subjects, 33 schizophrenic and 33 normal subjects were included in the study. Schizophrenic subjects performed poorly on CDT and MMSE compared to the normal subjects. The difference between the mean scores was statistically significant. The examination errors on the clock drawing test was more apparent among schizophrenic subjects. There were positive correlations between CDT and MMSE, and BPRS and PANSS. Negative correlations were observed between the cognitive performance and the symptom severity of schizophrenia.
CONCLUSION: Schizophrenic subjects performed poorly on CDT compared to the normal subjects, thus it is useful in detecting cognitive impairment. Likewise, CDT performance correlates well with symptom severity. Its availability and simplicity makes it very useful in detecting cognitive impairment in our clinical practice.