SEARCH

SEARCH BY CITATION

Keywords:

  • Bipolar disorder;
  • cognition;
  • euthymia;
  • quality of life

Abstract

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

Purpose

Little is known about quality of life (QOL) in Chinese patients with bipolar disorder (BD) in remission (euthymia). This study examined the QOL of such a cohort of BD patients and its demographic, clinical, and cognitive correlates.

Design and Methods

Forty-seven euthymic BD patients and 47 matched healthy controls formed the study sample. Socio-demographic characteristics, prospective memory, retrospective memory, intelligence quotient, and executive functioning were measured in all participants together with patients' psychopathology ratings.

Findings

Multivariate analyses revealed that compared to controls, euthymic BD patients had significantly lower satisfaction with physical QOL domain. Only subthreshold depressive symptoms independently contributed to reduced satisfaction with physical and environmental QOL domains, whereas no variable predicted its psychological and social domains.

Practice Implications

Contrary to findings from Western settings, demographic variables and cognitive deficits had no associations with any QOL domain in euthymic Chinese BD patients. Control of subthreshold depressive symptoms in euthymic BD patients might enhance their QOL.

Quality of life (QOL), defined as “an individual's perception of one's position in life in relation to goals, expectations, standards and concerns in the context of the culture and value systems in which one lives” (World Health Organization [WHO], 1998), has been used as an outcome measure to evaluate the effectiveness of mental health services (Kurtz, Bronfeld, & Rose, 2012).

There have been relatively few studies examining QOL in bipolar disorder (BD; Michalak, Yatham, & Lam, 2005) probably because until recently it was assumed that BD patients sufficiently recover between episodes (Malhi et al., 2007). However, previous studies found that neurocognitive deficits persist throughout the illness and functional impairments are not fully reversed even in remission (euthymia) (Martinez-Aran et al., 2004; Thompson et al., 2005), which, in turn, lowers patients' QOL (Brissos, Dias, & Kapczinski, 2008).

There has been growing interest in QOL research in BD in recent years (Gutierrez-Rojas et al., 2008). Western studies indicated that BD patients had worse QOL in all domains compared to healthy controls (HCs), and a number of demographic and clinical correlates, such as depressive symptoms, cognitive deficits, length of illness, and older age, were found to contribute to the poor QOL in BD (Brissos, Dias, Carita, & Martinez-Aran, 2008; Brissos, Dias, & Kapczinski, 2008; Gutierrez-Rojas et al., 2008).

Sociocultural and ethnic differences could influence psychiatric patients' QOL (Warner et al., 1998; Xiang, Chiu, & Ungvari, 2010). Most studies examining QOL in BD have been carried out in Western settings; therefore, their results may not be applicable to non-Western sociocultural environments.

There has been no study to date testing QOL in Chinese-remitted (euthymic) BD patients and its potential associations with demographic and clinical characteristics and cognitive deficits. The aims of this study were to compare QOL between euthymic BD patients and HCs in a Chinese sample and to explore the relationships between QOL and socio-demographic and clinical variables and cognitive functions including intelligence quotient (IQ), executive functioning, and retrospective (RM; memory of past information) and prospective memories (PM; memory of activities to be performed in the future) in patients. Only euthymic BD patients were included in this study to minimize mood-dependent bias on QOL and to explore to what extent QOL is a state or a trait characteristic of the illness.

There are two ways to evaluate QOL. One is the subjectively reported measures of QOL and the other is objectively rated by relatives and/or mental health professionals. It was reported that there is no, or merely weak correlation, between subjective and objective QOL (Fitzgerald et al., 2001), and QOL measures have veered preferentially toward subjective evaluation (Kurtz et al., 2012). Therefore, in this study we only focus on subjective QOL.

Methods

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

Study Settings and Participants

This cross-sectional study was conducted from May 2010 to March 2011. Forty-seven patients with BD were consecutively recruited from the Outpatient Department of a university-affiliated psychiatric hospital in Beijing, China. The hospital has 800 beds, completes approximately 1,100 outpatient visits daily, and serves 19 million people. Forty-seven HCs matched according to age (±2 years) and education (±2 years) were recruited from the community by advertisements followed by a diagnostic interview to confirm that HCs had no major medical conditions, and neurological or psychiatric disorders. The study protocol was approved by the Clinical Research Ethics Committee of Beijing Anding Hospital. Written consent to participate in the study was obtained from each participant. Patients entered the study if they satisfied the following inclusion criteria: (a) diagnosis of BD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) (American Psychiatric Association [APA], 1994) established by administering the Structural Clinical Interview for DSM-IV (First, Spitzer, Gibbon, & Williams, 1996); (b) remission lasting at least 6 months; (c) age between 16 and 50 years; (d) Chinese ethnicity; (e) at least primary level of education and the ability to understand the requirements of the study; and (f) euthymia defined as the sum score of the 17-item Hamilton Depression Rating Scale (HAM-D; Hamilton, 1960) ≤ 7, and that of the 11-item Young Mania Rating Scale (YMRS; Young, Biggs, Ziegler, & Meyer, 1978) ≤ 6. The exclusion criteria included (a) a history of, or current, significant medical or neurological condition(s) including learning disability; (b) a history of, or current, significant drug/alcohol abuse; and (c) electroconvulsive treatment in the past 12 months.

According to the finding of an earlier study examining QOL in patients with euthymic BD in Europe (Dias, Brissos, Frey, & Kapczinski, 2008), the effect size between patients and HCs in QOL was 0.9. Using power calculation (Cohen, 1988), the minimum number of patients needed to achieve 80% power will be 21, respectively, at a = .05 (two tailed). In order to assure enough power obtained in Chinese patients, the sample size in each group was 47 in this study.

Outcome Measures and Assessment

The participants' basic socio-demographic and clinical variables were collected with a questionnaire designed for the study. The severity of depressive and manic symptoms was measured by the HAM-D and the YMRS, respectively.

The following neuropsychological test battery was used to measure IQ, executive functioning, and RM: (a) Raven's Progressive Matrices for IQ (Raven, 1965); (b) the Wisconsin Card Sorting Test (Heaton, Chelune, Talley, Kay, & Curtiss, 1993) for executive functions; and (c) the immediate Logical Memory subtest of the Wechsler Memory Scale-Revised (Wechsler, 1987) for RM. PM was assessed with the validated Chinese version of the Cambridge PM Test (C-CAMPROMPT; Lou, Dou, Zheng, Y.B., & Man, 2009). In this test, participants are asked to remember to carry out three time-based (TB-PM; remembering to perform an action at a specific time without explicit prompts) and three event-based tasks (EB-PM; remembering to perform an action triggered by an external event) at different intervals, while performing a filler activity following both verbal and written instructions. The C-CAMPROMPT generates scores on three TB-PM and three EB-PM tasks, each scoring a maximum of 6 with a sum score ranging from 0 to 36. QOL was assessed with the Chinese version of the World Health Organization Quality of Life Schedule-Brief (WHOQOL-BREF; Fang, Hao, & Li, 1999; WHO, 1998). The Chinese version of the WHOQOL-BREF is a 28-item, self-administered generic questionnaire, which covers four domains: physical health, psychological health, social relationships, and environmental domains. Patients assess their satisfaction of each item on a 5-point scale (from 1 = “very dissatisfied” to 5 = “very satisfied”).

Procedures

Patients completed all aforementioned assessments in the hospital within a day, whereas the HCs completed only the cognitive and QOL assessments. All tests were administered in one session that lasted 2–3 hr. A qualified psychiatrist (JZ) rated psychiatric symptoms and administered the neuropsychological tests.

Statistical Analysis

The data were analyzed using SPSS 13.0 for Windows. Comparisons between patients and controls with respect to socio-demographic and clinical characteristics, neurocognitive tests, and QOL were performed by an independent sample t test, Mann–Whitney U test, and chi-square test, as appropriate. The relationship of QOL with socio-demographic and clinical characteristics and neurocognitive tests was analyzed with Spearman rank correlation analysis. Stepwise multiple linear regression analysis was performed to identify factors contributing to each QOL domain. All variables that showed significant bivariate correlation relationships with QOL were entered as independent variables with each QOL domain separately as dependent variable. Two-tailed tests were used in the analyses with the significance level set at 0.05.

Results

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

Table 1 presents the demographic and clinical factors of the study sample. Patients had lower education level, lower scores on TB-PM and EB-PM, and a higher score on the perseverative errors of the Wisconsin Card Sorting Test (WCST-PE) than the controls, indicating worse performance in these domains. There was no significant difference in any QOL domains between the two groups. After controlling for the potential confounding effects of education level, WCST-PE, TB-PM, and EB-PM by analysis of covariance, the patients had lower satisfaction within physical QOL domain (F(1, 88) = 5.9, p = .02), while there was still no difference in the psychological (F(1, 88) = .5, p = .5), social (F(1, 88) = 2.0, p = .2), and environmental QOL domains (F(1, 88) = .1, p = .7). Table 2 shows the correlations between demographic and clinical characteristics, cognitive tests, and different QOL domains. Residual depressive symptoms were inversely associated with physical and environmental QOL domains. Results of multiple regression analyses with the stepwise method examining the contributors to QOL are shown in Table 3. Residual depressive symptoms were independently associated with lower satisfaction with physical and environmental domains.

Table 1. Comparison of Patients and Healthy Controls With Respect to Demographic and Clinical Characteristics
 Patients (n = 47)Controls (n = 47)Statistics
NPercentNPercentχ2dfp value
Men 2961.72246.82.11.1
 MSDMSDt/zdfp value
  1. a

    Mann–Whitney U test. HAM-D, Hamilton Depression Rating Scale; YMRS, Young Mania Rating Scale; WMS-R, Wechsler Memory Scale-Revised; TB-PM, time-based prospective memory; EB-PM, event-based prospective memory; WCST-TC, Wisconsin Card Sorting Test (total correct); WCST-PE, Wisconsin Card Sorting Test (perseverative errors); WCST-TE, Wisconsin Card Sorting Test (total error); WCST-CC, Wisconsin Card Sorting Test (categories completed); QOL, quality of life.

Age (year)28.78.928.77.6−0.0392.98
Education (year)14.32.115.52.4−2.692.01
Age at onset (year)24.08.3
Length of illness (year)4.73.3
HAM-D total score4.31.2
YMRS total score3.61.7
Raven's raw score91.018.293.710.8−0.992.4
WMS-R logical memories, immediate93.017.295.510.9−0.892.4
TB-PM9.84.313.22.4−4.692<.001
EB-PM14.12.915.52.6−2.592.02
WCST-PE10.35.97.93.62.492.02
WCST-CC4.01.74.50.9−0.8a.4
QOL physical13.72.814.61.9−1.892.08
QOL psychological13.62.413.91.7−0.792.5
QOL social13.42.814.32.2−1.792.1
QOL environmental14.02.913.81.40.492.7
Table 2. Correlations Between Socio-Demographic and Clinical Characteristics and QOL in Bipolar Affective Disorder in Remission
 QOL domains
Physical rPsychological rSocial rEnvironmental r
  1. *p < .01; HAM-D, Hamilton Depression Rating Scale; YMRS, Young Mania Rating Scale; WMS-R, Wechsler Memory Scale-Revised; TB-PM, time-based prospective memory; EB-PM, event-based prospective memory; WCST-TC, Wisconsin Card Sorting Test (total correct); WCST-PE, Wisconsin Card Sorting Test (perseverative errors); WCST-TE, Wisconsin Card Sorting Test (total error); WCST-CC, Wisconsin Card Sorting Test (categories completed); QOL, quality of life.

Patients (n = 47)    
Men−0.020.030.05−0.12
Age (year)0.070.050.250.26
Age at onset (year)0.080.060.260.23
Length of illness (year)−0.05−0.030.020.14
HAM-D total score−0.34*−0.19−0.24−0.36*
YMRS total score−0.14−0.16−0.12−0.25
Raven's raw score−0.130.040.08−0.02
WMS-R logical memories, immediate−0.020.150.110.04
TB-PM−0.19−0.080.030.02
EB-PM0.090.11−0.010.12
WCST-PE0.17−0.090.06−0.001
WCST-CC−0.25−0.06−0.12−0.08
Table 3. Stepwise Multiple Regression Analysis With Each QOL Domain as Dependent Variables and Selected Factors as Predictorsa
Dependent variablePredictorβp95% CI
  1. a

    There was no variable significantly associated with psychological and social QOL domains in correlation analyses. CI, confidence interval; HAM-D, Hamilton Depression Rating Scale; QOL, quality of life.

Physical QOL    
Adjusted R2 = .09; F(1, 45) = 5.8; p = .02HAM-D−0.3.02−1.4, −0.1
Environmental QOL    
Adjusted R2 = .11; F(1, 45) = 6.6; p = .01HAM-D−0.04.01−1.5, −0.2

Discussion

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

Patients with BD in remission may face multiple disadvantages in daily living due to neurocognitive deficits, adverse effects of psychotropic medications, stigma and discrimination related to their illness, and having inadequate personal and material resources (Martinez-Aran et al., 2004; Thompson et al., 2005; Yen et al., 2008). Consequently it was expected that BD patients in this study would have poorer satisfaction with QOL than the controls. The results did not support this expectation since there were no significant differences between the two groups in any of the QOL domains in the univariate analyses. Patients had lower satisfaction within the physical QOL domain after controlling for the confounding effects of education, PM, and Wisconsin Card Sorting Test (categories completed). This result suggests that remitted, euthymic BD patients still struggle with daily activities, treatment adherence, pain and discomfort, sleep and rest, and energy and fatigue as measured by physical domain of WHOQOL-BREF (WHO, 1998). The main reason for this could be the adverse effects of psychotropic drugs, less self-care, neglect of physical condition, poorer medical care, and poorer nutrition that lower patients' scores on the physical QOL domain. There was no difference between the two groups in the life satisfaction with psychological, social, and environmental QOL domains, a finding quite different from those obtained in Western settings (Brissos, Dias, Carita, et al., 2008; Brissos, Dias, & Kapczinski, 2008). These results seem to support the notion that sociocultural and ethnic factors considerably influence psychiatric patients' QOL (Xiang et al., 2010). In China, the traditional Confucian ideas remain influential, which underline modesty or “moderation” (zhong yong zhi dao) and oppose polarity or extremes (Xiang et al., 2010). This principle is well exemplified in the public attitudes toward different psychiatric disorders. For example, the general population in China is very sensitive to schizophrenia, particularly those with positive symptoms. These patients are usually more stigmatized and are often committed to psychiatric hospitals even if they are clinically stable because they are commonly believed as threats to the public (Xiang, Weng, Leung, Tang, & Ungvari, 2008). In contrast, mood disorders, including BDs and major depressive disorder, are perceived as social and psychological problems by the Chinese public. As a result, these patients are expected to have a full recovery with good social and occupational functioning after having a good rest at home, or receive medication treatment and psychological counseling, and are better accepted by their family and society. Such different attitudes would have a strong impact on social supports from family and society, and patients' self-esteem and coping mechanisms, which, in turn, influence life satisfaction with psychological, social, and environmental QOL domains. However, these are speculations; future studies exploring the impact of Confucian culture on QOL of different psychiatric disorders are warranted.

Depressive symptoms are one of the potent contributors to low QOL in BD (Kebede et al., 2006; Sierra, Livianos, & Rojo, 2005) and schizophrenia (Xiang et al., 2010). Subthreshold depressive symptoms were quite mild in the current sample (HAM-D total score: 4.3 ± 1.2), but still significantly predicted lower QOL, as reported in earlier studies (Brissos, Dias, Carita, et al., 2008; Brissos, Dias, & Kapczinski, 2008; Gutierrez-Rojas et al., 2008). More importantly, residual depressive symptoms were the only contributor to QOL in multivariate analyses in our investigation. In addition, it was reported that manic symptoms influence QOL in a bimodal pattern: severe mania is associated with higher life satisfaction with QOL due to the elevated mood, impaired judgment, and lack of insight, whereas mild mania is related to reduced life satisfaction with QOL probably owing to the stigma due to the illness (Gazalle, Frey, et al., 2007; Gazalle, Hallal, et al., 2007; Ghaemi & Rosenquist, 2004). It was therefore expected that residual manic symptoms in this study would be related to lower life satisfaction with QOL, but the results did not support this hypothesis.

Patients with BD in remission suffer from cognitive deficits related to impaired memory and executive dysfunction (Lee et al., 2010; Robinson et al., 2006; Torres, Boudreau, & Yatham, 2007). Western studies found that cognitive deficits were strongly associated with lower satisfaction with QOL (Brissos, Dias, Carita, et al., 2008; Brissos, Dias, & Kapczinski, 2008). This study failed to support this finding; patients had PM and executive function deficits, but neither of them were associated with reduced satisfaction with QOL. According to the distress/protection model of QOL (Voruganti, Heslegrave, Awad, & Seeman, 1998), QOL is the outcome of an interaction between protective (e.g., self-esteem, social support, and avoidance) and distressing factors (e.g., psychopathology and drug side effects). QOL increases if protective factors (e.g., intensive social support by families in traditional Chinese societies) predominate over distressing factors (e.g., cognitive deficits), which may explain the nonsignificant association between QOL and cognitive deficits in this study. Previous studies suggested that age (Fenn et al., 2005) and earlier age at onset (Perlis et al., 2004) contribute to poor QOL, but these findings are not replicated for Chinese patients in this study.

Several methodological limitations of the study need to be addressed. First, psychiatric symptoms and the cognitive tests were evaluated only by one rater. Ideally, the different aspects of the assessment should have been performed by different researchers blind to each other's findings. Second, the study was cross-sectional, therefore the causality of relationships between QOL and other variables could not be explored. Third, a larger sample size would have allowed the use of more complex regression models to explore the impact of a wider range of clinical and psychological factors on QOL, and the comparison between subtypes of BD (BD I, BD II and BD not otherwise specified). Finally, the DSM-IV diagnostic system used in this study was released by the American Psychiatric Association (APA) in 1994, but it is still the current diagnostic system used in both research and practice. The APA will publish the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders in May 2013 (http://www.dsm5.org/Pages/Default.aspx). The strengths of this study include the standardized assessments of QOL, neuropsychology, and clinical status, and the homogeneous sample that comprised only patients with euthymic BD.

In summary, poorer satisfaction with QOL in physical domain does persist in patients with BD even in remission. The findings of this study provide useful information for psychiatric nursing practice and an opportunity to develop a person-centric approach to the care of Chinese patients with BD in the community. It is recommended that psychiatric nurses should perform assessment of QOL and depression for clinically stabile patients with BD in order to make informed decisions about therapeutic interventions. The aims of the nursing interventions are to decrease the severity of depression and improve QOL for this population by providing psychoeducation for patients and their families about the illness and self-management techniques. This approach would also serve to establish and maintain a therapeutic alliance with patients with BD who are prone to frequent relapse.

Previous studies (Chan & Yu Iu, 2004) suggested that one of the most effective ways to facilitate recovery in persons with severe psychiatric disorders and improve their QOL is to allocate them to community psychiatric nurses (CPNs). CPNs could assess patients' needs and help coordinate all available resources based on the case management model. This model has been implemented in several Western countries with great success and should also be developed in China.

Acknowledgments

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

This study was supported by the National Natural Science Foundation of China (Grant No. 30800367, 30770776) and the Beijing Sciences and Technology Nova Program (Grant No. 2008B59). The authors are grateful to the researchers who developed CAMPROMT, Barbara A Wilson, Hazel Emslie, Jennifer Foley, Agnes Shiel, Peter Watson, Kari Hawkins, Yvonne Groot, and Jonathan J Evans, and for permission to use by Pearson Assessment. They also thank all of the patients and healthy controls involved in the project for their assistance.

Author contributions

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References

Study design: YTX, JJZ, CYW, FCZ, HFKC. Data collection and analysis: YTX, JJZ, CYW, FCZ. Manuscript preparation: YTX, LJL, LBD, FD, GSU, XYZ, DHKS, RWCA, WKT, DM, HFKC.

References

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Author contributions
  8. References
  • American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
  • Brissos, S., Dias, V. V., Carita, A. I., & Martinez-Aran, A. (2008). Quality of life in bipolar type I disorder and schizophrenia in remission: Clinical and neurocognitive correlates. Psychiatry Research, 160, 5562.
  • Brissos, S., Dias, V. V., & Kapczinski, F. (2008). Cognitive performance and quality of life in bipolar disorder. Canadian Journal of Psychiatry, 53, 517524.
  • Chan, S., & Yu Iu, W. (2004). Quality of life of clients with schizophrenia. Journal of Advanced Nursing, 45, 7283.
  • Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Erlbaum.
  • Dias, V. V., Brissos, S., Frey, B. N., & Kapczinski, F. (2008). Insight, quality of life and cognitive functioning in euthymic patients with bipolar disorder. Journal of Affective Disorders, 110, 7583.
  • Fang, J. Q., Hao, Y. T., & Li, C. X. (1999). Reliability and validity for Chinese version of WHO quality of life scale (in Chinese). Chinese Mental Health Journal, 13, 203205.
  • Fenn, H. H., Bauer, M. S., Altshuler, L., Evans, D. R., Williford, W. O., Kilbourne, A. M. et al. (2005). Medical comorbidity and health-related quality of life in bipolar disorder across the adult age span. Journal of Affective Disorders, 86, 4760.
  • First, M., Spitzer, R., Gibbon, M., & Williams, J. (1996). Structured clinical interview for DSM-IV Axis I Disorders (SCID), clinician version. Washington, DC: American Psychiatric Press.
  • Fitzgerald, P. B., Williams, C. L., Corteling, N., Filia, S. L., Brewer, K., Adams, A., … Kulkarni, J. (2001). Subject and observer-rated quality of life in schizophrenia. Acta Psychiatrica Scandinavica, 103, 387392.
  • Gazalle, F. K., Frey, B. N., Hallal, P. C., Andreazza, A. C., Cunha, A. B., Santin, A., & Kapczinski, F. (2007). Mismatch between self-reported quality of life and functional assessment in acute mania: A matter of unawareness of illness? Journal of Affective Disorders, 103, 247252.
  • Gazalle, F. K., Hallal, P. C., Andreazza, A. C., Frey, B. N., Kauer-Sant'Anna, M., Weyne, F., & Kapczinski, F. (2007). Manic symptoms and quality of life in bipolar disorder. Psychiatry Research, 153, 3338.
  • Ghaemi, S. N., & Rosenquist, K. J. (2004). Is insight in mania state-dependent?: A meta-analysis. Journal of Nervous and Mental Disease, 192, 771775.
  • Gutierrez-Rojas, L., Gurpegui, M., Ayuso-Mateos, J. L., Gutierrez-Ariza, J. A., Ruiz-Veguilla, M., & Jurado, D. (2008). Quality of life in bipolar disorder patients: A comparison with a general population sample. Bipolar Disorders, 10, 625634.
  • Hamilton, M. (1960). A rating scale for depression. Journal of Neurology, Neurosurgery, and Psychiatry, 23, 5662.
  • Heaton, R., Chelune, G. J., Talley, J. L., Kay, G. G., & Curtiss, G. (1993). Wisconsin Card Sorting Test (WCST) manual, revised and expanded (2nd ed.). Odessa, FL: Psychological Assessment Resources.
  • Kebede, D., Alem, A., Shibire, T., Deyassa, N., Negash, A., Beyero, T., … Fekadu, A. (2006). Symptomatic and functional outcome of bipolar disorder in Butajira, Ethiopia. Journal of Affective Disorders, 90, 239249.
  • Kurtz, M. M., Bronfeld, M., & Rose, J. (2012). Cognitive and social cognitive predictors of change in objective versus subjective quality-of-life in rehabilitation for schizophrenia. Psychiatry Research, 200, 102107.
  • Lee, E., Xiang, Y. T., Man, D., Au, R. W., Shum, D., Tang, W. K., … Ungvari, G. (2010). Prospective memory deficits in patients with bipolar disorder: A preliminary study. Archives of Clinical Neuropsychology, 25, 640647.
  • Lou, Z. L., Dou, Z. L., Zheng, J. L., Y.B., C., & Man, D. W. K. (2009). The study of the Chinese version of Cambridge Prospective Memory Test (CAMPROMPT) for traumatic brain injury (unpublished master's thesis). Sun Yat Sen University, Guangzhou, P.R. China.
  • Malhi, G. S., Ivanovski, B., Hadzi-Pavlovic, D., Mitchell, P. B., Vieta, E., & Sachdev, P. (2007). Neuropsychological deficits and functional impairment in bipolar depression, hypomania and euthymia. Bipolar Disorders, 9, 114125.
  • Martinez-Aran, A., Vieta, E., Reinares, M., Colom, F., Torrent, C., Sanchez-Moreno, J., … Salamero, M. (2004). Cognitive function across manic or hypomanic, depressed, and euthymic states in bipolar disorder. American Journal of Psychiatry, 161, 262270.
  • Michalak, E. E., Yatham, L. N., & Lam, R. W. (2005). Quality of life in bipolar disorder: A review of the literature. Health and Quality of Life Outcomes, 3, 72.
  • Perlis, R. H., Miyahara, S., Marangell, L. B., Wisniewski, S. R., Ostacher, M., DelBello, M. P., … Nierenberg, A. A. (2004). Long-term implications of early onset in bipolar disorder: Data from the first 1000 participants in the systematic treatment enhancement program for bipolar disorder (STEP-BD). Biological Psychiatry, 55, 875881.
  • Raven, J. C. (1965). Guide to using the Coloured Progressive Matrices. London: H.K. Lewis.
  • Robinson, L. J., Thompson, J. M., Gallagher, P., Goswami, U., Young, A. H., Ferrier, I. N., & Moore, P. B. (2006). A meta-analysis of cognitive deficits in euthymic patients with bipolar disorder. Journal of Affective Disorders, 93, 105115.
  • Sierra, P., Livianos, L., & Rojo, L. (2005). Quality of life for patients with bipolar disorder: Relationship with clinical and demographic variables. Bipolar Disorders, 7, 159165.
  • Thompson, J. M., Gallagher, P., Hughes, J. H., Watson, S., Gray, J. M., Ferrier, I. N., & Young, A. H. (2005). Neurocognitive impairment in euthymic patients with bipolar affective disorder. British Journal of Psychiatry, 186, 3240.
  • Torres, I. J., Boudreau, V. G., & Yatham, L. N. (2007). Neuropsychological functioning in euthymic bipolar disorder: A meta-analysis. Acta Psychiatrica Scandinavica. Supplementum, 1726.
  • Voruganti, L., Heslegrave, R., Awad, A. G., & Seeman, M. V. (1998). Quality of life measurement in schizophrenia: Reconciling the quest for subjectivity with the question of reliability. Psychological Medicine, 28, 165172.
  • Warner, R., de Girolamo, G., Belelli, G., Bologna, C., Fioritti, A., & Rosini, G. (1998). The quality of life of people with schizophrenia in Boulder, Colorado, and Bologna, Italy. Schizophrenia Bulletin, 24, 559568.
  • Wechsler, D. (1987). Wechsler memory scale-revised. San Antonio, TX: Psychological Corporation.
  • World Health Organization. (1998). Development of the World Health Organization WHOQOL-BREF quality of life assessment. The WHOQOL Group. Psychological Medicine, 28, 551558.
  • Xiang, Y. T., Chiu, H. F., & Ungvari, G. S. (2010). Quality of life and mental health in Chinese culture. Current Opinion in Psychiatry, 23, 4347.
  • Xiang, Y. T., Weng, Y. Z., Leung, C. M., Tang, W. K., & Ungvari, G. S. (2008). Subjective quality of life in outpatients with schizophrenia in Hong Kong and Beijing: Relationship to socio-demographic and clinical factors. Quality of Life Research, 17, 2736.
  • Yen, C. F., Cheng, C. P., Huang, C. F., Yen, J. Y., Ko, C. H., & Chen, C. S. (2008). Quality of life and its association with insight, adverse effects of medication and use of atypical antipsychotics in patients with bipolar disorder and schizophrenia in remission. Bipolar Disorders, 10, 617624.
  • Young, R. C., Biggs, J. T., Ziegler, V. E., & Meyer, D. A. (1978). A rating scale for mania: Reliability, validity and sensitivity. British Journal of Psychiatry, 133, 429435.