Psychiatry and Clinical Neurosciences 2011; 65: 70–76
doi:10.1111/j.1440-1819.2010.02166.x
Regular Article
Is a patient-administered depression rating scale valid for detecting cognitive deficits in patients with major depressive disorder? pcn_2166
70..76
Tieng-Ts Hueng, MD,1 I. Hui Lee, MD,2,3 Yuh-Juh Guog, MD,1 Kao Chin Chen, Shu Shin Chen, MD,1 Shu Ping Chuang, MD,1 Tzung Lieh Yeh, MD2,3 and Yen Kuang Yang, MD2,3*
MD,2,3
1
Department of Psychiatry, Zuoying Armed Forces General Hospital, Kaohsiung and 2Department of Psychiatry, National Cheng Kung University Hospital and 3Department of Psychiatry, College of Medicine, National Cheng Kung University, Tainan, Taiwan
Aims: Although cognitive deficits are a common and potentially debilitating feature of major depressive disorder (MDD), such subjective declines in cognitive function are seldom validated by objective methods as a clinical routine. The aim of this study was to validate the Taiwanese Depression Questionnaire (TDQ) for detecting cognitive deficits in a sample of drug-free patients with MDD. Methods: The subjects consisted of 40 wellcharacterized medication-free patients with MDD and 40 healthy controls. Clinical and neuropsychological assessments, including the Wisconsin Card Sorting Test, the Wechsler Memory Scale–Revised, the Continuous Performance Test, and the Finger-Tapping Test, were administered at the time of recruitment.
performance were significantly poorer in patients with MDD. The performances of verbal and delayed memory of the Wechsler Memory Scale–Revised were correlated with the cognitive domains of the TDQ. Generalization of our results must be undertaken with caution considering the relatively small sample size, which could lead to increased b-error.
Conclusion: Cognitive subdomains might be considered important for including in patient-administered questionnaires used to measure symptoms of MDD when developing a new scale. Key words: cognitive deficits, major depression, neurocognitive functions, Taiwanese Depression Questionnaire.
Results: Factor analyses of the TDQ yielded three Memory, attention and psychomotor
factors.
HE INCLUSION OF cognitive symptoms in the DSM-IV criteria for major depressive episodes highlights the importance of cognition. For example, the criteria for the diagnosis of this condition include a diminished ability to concentrate, indecisiveness, and psychomotor retardation or agi-
T
*Correspondence: Yen Kuang Yang, MD, Department of Psychiatry, College of Medicine, National Cheng Kung University, 138 Sheng Li Road, Tainan 70428, Taiwan. Email:
[email protected] Received 30 September 2008; revised 21 October 2010; accepted 1 November 2010.
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tation. There is a growing body of evidence of a significant reduction in neurocognitive functions in major depressive disorder (MDD),1 and depressionrelated disturbances of cognitive function have been demonstrated in a range of domains, including attention,2–4 memory,5,6 executive functions,7–10 and psychomotor functions.11 However, findings to date are varied,12 with many factors potentially contributing to inconsistencies between studies, including age, hospitalization duration, severity and subtype of depression, and the effect of psychotropic medication.13,14
© 2011 The Authors Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology
Psychiatry and Clinical Neurosciences 2011; 65: 70–76
Although cognitive deficits are a common and potentially debilitating feature of MDD, subjective cognitive decline is seldom validated by objective methods. Only a limited number of items pertain to neurocognitive decline in the most widely used depression rating scales, for example, the Hamilton Depression Rating Scale (HDRS)15 and the Beck Depression Inventory (BDI).16 However, in a recently developed patient-administered depression questionnaire, more comprehensive incorporation of cognitive items was attempted,17,18 although the validity concerning the neurocognitive domain of depression has not yet been confirmed. The aims of this study were to: (i) validate the Taiwanese Depression Questionnaire (TDQ) for cognitive deficits in a sample of patients with MDD; and (ii) compare the cognitive function of depressed patients with that of their controls.
METHODS Subjects We recruited 40 patients with a mean age of 38.72 ⫾ 13.02 years (11 men and 29 women), who were evaluated with the Mini-International Neuropsychiatric Interview19 and were diagnosed as having MDD according to the criteria of the DSM-IV at the outpatient clinic of the Department of Psychiatry, National Cheng Kung University, Tainan, Taiwan. Before any procedure was performed, informed consent was obtained from patients and healthy controls. The Ethical Committee for Human Research of the hospital approved the study protocol. Patients were included if they had not received any psychotropic medication for more than 3 months; and we excluded patients with: (i) a current diagnosis of dysthymia or other mental disorders; (ii) serious suicidal risk; or (iii) any acute or unstable medical condition. We also excluded patients who had undergone electroconvulsive therapy. Healthy controls (11 men and 29 women) who had been recruited from the community by advertisement for various studies were also enrolled in this study (Table 1). All participants confirmed that they were not taking antidepressants at the time of recruitment.
Questionnaire detecting cognition
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is a culturally relevant and subjective questionnaire in which patients are asked to indicate, on a 4-point Likert scale, whether and how often each item is experienced. The TDQ total score ranges from 0 to 54, and the higher the score, the more severe the level of depression. A cut-off score of 19 has a good validity (sensitivity = 0.89, specificity = 0.92). On examination of the internal consistency, Cronbach’s a coefficient of the questionnaire was 0.94. Three factors, somatic, affective and cognitive factors, were reported when the TDQ was developed; however, no detailed descriptions were included in the original article.17 Furthermore, the 17-item HDRS is an itemized questionnaire providing information on the affective and somatic symptoms of depression and was rated by a senior psychiatrist (Y.K.Y.) in this study.15
Wisconsin Card Sorting Test20 The Wisconsin Card Sorting Test (WCST) was conducted by an experienced clinical neuropsychologist. All definitions of the indices were as described in the WCST manual.20 We chose to analyze the most commonly used indices, ‘perseverative errors’ and ‘completed categories’, among the many indices of the WCST.21,22
Wechsler Memory Scale–Revised version23 The Wechsler Memory Scale–Revised version (WMS-R) test was administered by trained psychologists with masters’ degrees. This test comprises a series of 13 brief subtests that include assessment of: (1) information and orientation; (2) mental control; (3) figure memory; (4) logical memory I; (5) visual paired associates I; (6) verbal paired associates I; (7) visual reproduction I; (8) digit span; (9) visual memory span; (10) logical memory II; (11) visual paired associates II; (12) verbal paired associates II; and (13) visual reproduction II, each measuring a different facet of memory. Subtests 3–9 measure immediate learning, while the latter four subtests measure recall of the material learned in the previous subtests. All subtests except the information and mental control tests measure episodic learning of both verbal and figural materials.
Measurements
Continuous Performance Test24,25
All participants completed the TDQ.17 This questionnaire contains 18 items for depression symptoms; it
The Continuous Performance Test (CPT) is a vigilance task requiring the monitoring of rapid informa-
© 2011 The Authors Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology
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T-T. Hueng et al.
Psychiatry and Clinical Neurosciences 2011; 65: 70–76
Table 1. Clinical data of the patients with major depressive disorder and the controls Patients with MDD (n = 40)
Age (years) Sex Male Female Educational level (years) Duration of illness (years) HDRS TDQ Affective domain Cognitive domain Somatic domain Sum WMS-R Verbal memory index Visual memory index General memory index Attention/concentration Delayed-recall memory index WCST Perseverative errors Category completed CPT CPT unmasked d’ CPT masked d’ FTT Dominant hand
Controls (n = 40)
Mean
(SD)
Mean
(SD)
39.37
(13.96)
39.01
(12.77)
11 29 11.27 1.27 21.47
11 29 (3.69) (2.24) (5.07)
0.00
1.00
12.98
12.54 5.90 17.03 35.46
t / x2
P-value
0.12
0.90
(3.58)
-1.95
0.06
3.95
(1.89)
20.04
