Use of Clock Drawing Test as a Screening Tool for Cognitive Status Evaluation in Middle-Aged Patients with Depressive Disorder

Use of clock drawing test as a screening tool for cognitive status evaluation in middle-aged patients with depressive disorder Objective: The objective of this study was to evaluate the cognitive functions of middle-aged patients with depressive disorder by using the clock drawing test (CDT). Methods: In this case control study, the data from 96 patients with depressive disorder and 105 healthy controls, who were recruited from the Psychiatry and Family Medicine clinics, were analyzed. Sociodemographic and medical questionnaires were completed by the participants. Thereafter, the Mini Mental State Examination (MMSE) and CDT (reading and drawing) were conducted. The drawings were rated according to the scoring methods of Manos, Shulman, and Sunderland. The severity of depression was assessed by the Montgomery-Asberg Depression Rating Scale. Results: The mean age of the participants were 52.45 +/- 5.16 and 52.13 +/- 5.53 years for control and patient groups, respectively. The two groups did not differ in age, gender, educational level, or history of comorbid conditions (p>0.05). The mean duration of depressive illness was 63.41 +/- 86.42 months. The severity of depression was rated as mild, moderate, or severe in 16(16.7%), 70 (72.9%), and 10 (10.4%) of the patients, respectively. The MMSE scores were high (24-30) in 77 (80.2%) patients and 101 (96.2%) controls and were low (523) in 19 (19.8%) patients and 4 (3.8%) controls (p<0.01). Of the 101 controls with normal MMSE scores, 29 (28.7%), 28 (27.7%), and 9 (8.9%) had abnormal clock-drawing scores by the Manos, Shulman, and Sunderland methods, respectively. Of the 77 patients with normal MMSE scores, 49 (63.6%), 28 (36.3%), and 42 (54.5%) had abnormal clock-drawing scores by the Manos, Shulman, and Sunderland methods, respectively. The Pearson correlations of the MMSE with the Manos, Sunderland, and Shulman methods were r=0.52, r=0.48, and r=0.53, respectively and were all statistically significant (p<0.001). All participants in the control group read the indicated time correctly in clock-reading test. However, 92 out of 96 patients read the indicated time correctly. There was no impact of demographic characteristics, comorbid conditions, and duration of depression on the CDT performance of the subjects. Conclusion: The cognitive functions of middle-aged patients with depressive disorder could be screened by the CDT. The fact that the CDT is sensitive enough to detect the cognitive impairment inherent in depressive disorder, as well as being correlated with symptom severity, makes this test useful in the assessment of cognitive status in depression (Shulman method; r=0.26, p<0.05).