Kwok-Chu Tso

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (7)19.56 Total impact

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    ABSTRACT: Bipolar disorder is often unrecognised and misdiagnosed in the general psychiatric setting. This study compared the psychometric properties of the Mood Disorder Questionnaire (MDQ) and the Hypomania Checklist-32 (HCL-32), examined the clinical predictors of bipolar disorder and determined the best approach for screening previously unrecognised bipolar disorder in a general psychiatric clinic. A random sample of 340 non-psychotic outpatients with no previous diagnosis of bipolar disorder completed the MDQ and HCL-32 during their scheduled clinic visits. Mood and alcohol/substance use disorders were reassessed using a telephone-based Structured Clinical Interview for DSM-IV. We found that the HCL-32 had better psychometric performance and discriminatory capacity than the MDQ. The HCL-32's internal consistency and 4-week test-retest reliability were higher. The area under the curve was also greater than that of the MDQ at various clustering and impairment criteria. The optimal cut-off of the MDQ was co-occurrence of four symptoms with omission of the impairment criterion; for the HCL-32, it was 11 affirmative responses. Multivariable logistic regression found that bipolar family history was associated with an increased risk of bipolar disorder (odds ratio=4.93). The study showed that simultaneous use of the HCL-32 and bipolar family history was the best approach for detecting previously unrecognised bipolar disorder.
    Psychiatry Research 08/2011; 195(3):111-7. · 2.68 Impact Factor
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    ABSTRACT: Pain symptoms are frequent complaints in patients with major depressive disorder (MDD). Although it is known that pain intensity and pain-related cognition predict quality of life (QOL) in patients with chronic pain, limited studies have examined their roles in MDD. The study aimed to determine whether pain and pain catastrophizing were independent predictors of QOL in MDD after accounting for the impact of anxiety and depression. This is a prospective, naturalistic follow-up study. Ninety-one Chinese patients were enrolled during an acute episode of MDD, 82 of them were reassessed 3 months later using the same assessment on pain, anxiety, depression, and QOL. Pain intensity was evaluated using a verbal rating scale and a visual analog scale. Quality of life was assessed using the 36-item Short Form Health Survey. Pain-related cognition was assessed at baseline with the Pain Catastrophizing Scale. There was significant improvement in pain, anxiety, depression, and QOL from baseline to 3-month follow-up. Hierarchical regression analyses showed that pain intensity was significantly associated with QOL at baseline and 3 months. Pain complaint was more important than anxiety and depressive symptoms in predicting changes in both physical and psychosocial domains of QOL. After controlling for the severity of pain, anxiety, and depression, Pain Catastrophizing Scale score was independently associated with QOL in MDD. The study supports the specific role of pain and pain-related cognition in predicting QOL in depressed patients. Further studies targeting pain-related cognition for improving the outcome of MDD are necessary.
    Comprehensive psychiatry 06/2011; 53(4):387-95. · 2.08 Impact Factor
  • Ka-Fai Chung, Kwok-Chu Tso
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    ABSTRACT: The study aims to determine which dimensions of pain-somatosensory, affective, or evaluative-would predict unidimensional pain scores in patients with major depressive disorder (MDD); compare the results with findings in cancer and chronic musculoskeletal pain patients; and examine the relationship between pain complaints and psychopathology. This is a 3-month prospective, observational study. Ninety-one Chinese patients were enrolled during an acute episode of MDD. Multidimensional Affect and Pain Survey (MAPS) was used to assess the multidimensional aspects of pain. Unidimensional pain intensity was evaluated using verbal rating scale (VRS) and visual analog scale (VAS). Hamilton Rating Scale for Depression and Hospital Anxiety and Depression Scale were used to assess depressive and anxiety symptoms. The VRS and VAS pain scores were more highly correlated with MAPS somatosensory supercluster than with Hamilton Rating Scale for Depression, Hospital Anxiety and Depression Scale, and MAPS emotional and well-being superclusters. Hierarchical regression analyses showed that unidimensional pain scores were predicted better by MAPS somatosensory than by emotional clusters. The explained variance of VRS and VAS scores could be improved by 9% to 16% by adding somatosensory clusters after controlling for emotional clusters, whereas 1% to 4% of the variance was improved by adding emotional clusters after controlling for somatosensory clusters. Pain intensity was more closely related to anxiety symptoms than to depressive symptoms cross-sectionally and longitudinally. Our data suggest that pain and emotional symptoms in MDD are not entirely related. In cases in which pain symptoms are severe or remain persistent despite treatment of depression, specific strategy targeting pain may be needed.
    Comprehensive psychiatry 01/2011; 52(2):208-17. · 2.08 Impact Factor
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    ABSTRACT: To evaluate the efficacy and safety of electroacupuncture as an additional treatment for residual insomnia associated with major depressive disorder (MDD). Randomized, placebo-controlled. A psychiatric outpatient clinic. 78 Chinese patients with DSM-IV-diagnosed MDD, insomnia complaint, a Hamilton Rating Scale for Depression (HDRS(17)) score ≤ 18, and fixed antidepressant dosage. Electroacupuncture, minimal acupuncture (superficial needling at non-acupuncture points), or noninvasive placebo acupuncture 3 sessions weekly for 3 weeks. Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), HDRS(17), 1 week sleep diaries, and 3 day actigraphy were administered at baseline, 1 week post-treatment, and 4 week post-treatment. There was significant group by time interaction in ISI, PSQI, and sleep diary-derived sleep efficiency (mixed-effects models, P = 0.04, P = 0.03, and P = 0.01, respectively). Post hoc pairwise comparisons revealed that electroacupuncture and minimal acupuncture were more efficacious than placebo acupuncture in ISI and PSQI at 1 week and 4 week post-treatment. Minimal acupuncture resulted in greater improvement in sleep diary-derived sleep efficiency than placebo acupuncture at 1 week post-treatment. There was no significant between-group difference in actigraphy measures, depressive symptoms, daily functioning, and hypnotic consumption, and no difference in any measures between electroacupuncture and minimal acupuncture. Compared with placebo acupuncture, electroacupuncture and minimal acupuncture resulted in greater improvement in subjective sleep measures at 1 week and 4 week post-treatment. No significant difference was found between electroacupuncture and minimal acupuncture, suggesting that the observed differences could be due to nonspecific effects of needling, regardless of whether it is done according to traditional Chinese medicine theory.
    Sleep 01/2011; 34(6):807-15. · 5.10 Impact Factor
  • Ka-Fai Chung, Kwok-Chu Tso
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    ABSTRACT: Insomnia and pain are frequent complaints during the course of a major depressive episode. We analyzed the association between insomnia and pain symptoms using subjective and objective sleep measures. This is a prospective, naturalistic follow-up study in a university-based psychiatric unit. Ninety-one Chinese patients were enrolled during an acute episode of major depressive disorder (mean age=48years, 73 women); 82 of them were reassessed 3months later using the same assessment on sleep, pain, depressive, and anxiety symptoms. Clinician-rated insomnia symptoms were obtained using the insomnia items of the Hamilton Rating Scale for Depression. Subjective sleep disturbances were assessed using the Insomnia Severity Index (ISI). Detailed sleep pattern was acquired using sleep diary and actigraphy. Pain intensity was evaluated using a verbal rating scale, a visual analog scale, and a multidimensional pain scale. Cross-sectional analyses found that insomnia symptoms and quantitative sleep parameters were related to pain symptoms. The correlations between sleep and pain scores were more significant after 3months of pharmacotherapy as compared to baseline. After controlling for the severity of anxiety and depression, the ISI total score and actigraphy-derived wake after sleep onset and total sleep time remained significant in predicting pain. This study supports specific role of subjective sleep disturbances and actigraphic measures in predicting pain symptoms in major depressive disorder. Further studies using a micro-longitudinal design are necessary to find out the causal relationship between sleep and pain in depressed patients.
    Sleep Medicine 09/2010; 11(8):752-8. · 3.49 Impact Factor
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    ABSTRACT: The objective of the study was to determine the reliability and validity of a Chinese version of the Mood Disorder Questionnaire (MDQ) in the general population in Hong Kong. One thousand five hundred eighteen adults aged at least 18 years were randomly drawn from the general population and interviewed using a lay-administered version of the MDQ. A subsample of 114 randomly selected participants received a telephone-based Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition. Six subjects were diagnosed to have bipolar disorder (bipolar I = 1, bipolar II = 4, and bipolar not otherwise specified = 1), 13 had substance/alcohol use disorder, and 95 had neither bipolar nor substance/alcohol use disorder. We determined the internal consistency, factor structure, and concurrent validity of the Chinese MDQ. The Cronbach alpha coefficient of the Chinese MDQ was 0.78. Principal component analysis with varimax rotation indicated a "euphoria-irritability-racing thoughts" factor, an "energized-activity" factor, and a "risky behavior" factor, which explained 46.6% of the rotated variance. There were significant differences in MDQ scores between the bipolar and non-bipolar non-substance/alcohol use disorder groups. The performance of the Chinese MDQ for detecting bipolar disorder was limited by a low sensitivity. Using the original cutoff criterion, defined as clustering of 7 or more symptoms that caused moderate or severe problems, the sensitivity was 0%, whereas the overall specificity was 95.4%. Lowering the cutoff criterion to a symptom score of at least 7 that caused minor or more problems yielded the best sensitivity (0.50) and specificity (0.92). The Chinese MDQ is a reliable and valid measure of bipolar disorder in the community.
    Comprehensive psychiatry 01/2009; 50(5):471-6. · 2.08 Impact Factor
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    ABSTRACT: The aim of the present study was to determine the validity of a Chinese version of the Mood Disorder Questionnaire (MDQ) as a screening instrument for bipolar disorder in a psychiatric outpatient population in Hong Kong. A total of 185 patients primarily being treated for mood disorders were asked to fill in the Chinese MDQ and supply other personal data during their scheduled clinic visit. The mean age was 43.0 years and 65.9% were female. A subsample of 102 randomly selected subjects, stratified by the MDQ symptom score, received a telephone-based Structured Clinical Interview for DSM-IV (SCID). Sixty-two patients (60.8%) were suffering from bipolar disorder (bipolar I, n = 48; bipolar II, n = 9; bipolar disorder not otherwise specified, n = 5), 35 (34.3%) from depressive disorder, and one (1.0%) from substance dependence, while four (3.9%) were unaffected by either mood or alcohol/substance use disorder. The internal consistency, factor structure and operating characteristics of the Chinese MDQ were analyzed. The internal consistency of the Chinese MDQ, evaluated using Cronbach alpha, was 0.82. Principal component analysis with varimax rotation indicated an 'energized-activity' factor and an 'irritability-racing thoughts' factor, which explained 47.2% of the rotated variance. The optimal cut-off was seven or more manic symptoms occurring within the same time period, which yielded a sensitivity of 0.73 and a specificity of 0.88 for detecting bipolar disorder. An additional criterion that the symptoms cause impairment resulted in significant loss of sensitivity. The Chinese MDQ is a valid screening instrument for bipolar disorder in a psychiatric outpatient population.
    Psychiatry and Clinical Neurosciences 09/2008; 62(4):464-71. · 2.04 Impact Factor