Is quality of life associated with cognitive impairment in schizophrenia?

doi:10.1016/j.pnpbp.2004.11.006

Progress in Neuro-Psychopharmacology and Biological Psychiatry

Volume 29, Issue 2, February 2005, Pages 239-244

https://doi.org/10.1016/j.pnpbp.2004.11.006 Get rights and content

Abstract

Background

The subjectively assessed quality of life of schizophrenia patients is mostly lower than healthy subjects, and cognitive impairment is an integral feature of schizophrenia. The aims of the present study were to compare the quality of life and neurocognitive functioning between the patients with schizophrenia and the healthy subjects, and to examine the relationships between quality of life and neurocognitive functions among the patients with schizophrenia.

Methods

Thirty-eight patients with schizophrenia (15 women and 23 men) and 31 healthy individuals (18 women and 13 men) were included in the study. All participants were administered World Health Organization Quality of Life–Brief Form (WHOQOL-BREF) to assess their quality of life, and Digit Span Test (DST) and Controlled Oral Word Association Test (COWAT) for cognitive functions.

Results

The patients with schizophrenia demonstrated lower scores in physical (F=25.6, p=0.0001), psychological (F=15.85, p=0.0001) and social (F=37.7, p=0.0001) domains compared to control group. The patients with schizophrenia showed significantly lower scores on COWAT compared to healthy subjects (F=4.22, p=0.04). The social domain scores of WHOQOL correlated to DST total scores (r=0.45, p=0.007), DST forwards scores (r=0.54, p=0.001) and COWAT total scores (r=0.40, p=0.04) in patients with schizophrenia but not in the control group. The patients with lower level of cognitive functioning had lower scores on social domain of WHOQOL-BREF (z=−2.01, p=0.04).

Conclusion

Our results confirm that the cognitive deficits in executive function and working memory appear to have direct impact on the patients’ perceived quality of life especially in social domain which can either be a cause or a consequence of social isolation of patients with schizophrenia.

Introduction

Psychopathology can affect most aspects of life, such as physical and psychological state, as well as social, occupational and economic status. Decreased Quality of Life (QoL) is often an important cause or consequence of psychopathology and needs to be included in a comprehensive treatment plan (American Psychiatric Association, 1994). In psychiatry, the QoL concept is frequently used as a part of a multidimensional assessment of outcome in the evaluation of treatment efficacy. The QoL measures are especially important when treating patients with chronic conditions, such as schizophrenia, which significantly impair their life (Saleem et al., 2002). Every aspect of everyday life is affected, including where they live and work, what activities they can perform and how they interact with other people. The subjectively assessed QoL of patients with schizophrenia living in the community is mostly lower than healthy subjects (Bengtsson-Tops and Hansson, 1999, Hermann et al., 2002).

It is well known that cognitive deficits are an integral feature of schizophrenia. Some studies have found widespread impairments in many domains of neurocognitive function, including executive function, attention, perceptual/motor processing, vigilance, verbal learning and memory, verbal and spatial working memory and verbal fluency (Braff et al., 1991, Kenny and Meltzer, 1991, Saykin et al., 1994). However, in contrast to the studies reporting widespread cognitive dysfunction in schizophrenia, some studies have provided more selective cognitive dysfunction in patients with schizophrenia (Saykin et al., 1991). Cognition has been increasingly regarded as a crucial outcome in the assessment of treatment efficacy in schizophrenia as the neurocognitive deficits have been reported to be predictive of social functioning, occupational functioning and level of independence within the community in schizophrenia (Green, 1996, Meltzer et al., 1996, Velligan and Miller, 1999) which all can be included in QoL.

The purpose of this cross-sectional study is twofold. First, we attempt to examine the neurocognitive functioning and the quality of life of patients with schizophrenia compared to healthy subjects. Second, we attempt to examine the relationships between neurocognitive functioning and self-reported health related quality of life.

Section snippets

Patient population and study design

All subjects (15 women and 23 men) had a DSM-IV diagnosis of schizophrenia (American Psychiatric Association, 1994) who had been recruited from Psychiatry Department of Dokuz Eylul University in Izmir, Turkey. The exclusion criteria were as follows: (i) history of other concomitant Axis I disorder; (ii) past or present substance dependence/abuse; (iii) history of neurological disorder; and (iv) electroconvulsive therapy within the last 6 months. All patients were clinically stable on

Comparison of quality of life between patient and control groups

The patients with schizophrenia demonstrated lower scores in all domains whereas statistical significance was found in physical, psychological and social domains compared to control group (Table 2).

Comparison of cognitive functioning between patient and control groups

Two groups showed significant and nearly significant differences on scores of COWAT and DST, respectively. The patients with schizophrenia showed lower scores on COWAT and DST backwards section compared to healthy subjects (Table 3).

Relation of quality of life to cognition in patient and control groups

The social domain scores of WHOQOL were positively correlated to DST

Discussion

It has been clearly shown that individuals with schizophrenia have impaired neurocognitive functioning and reduced quality of life. However the relation of QoL to cognition has been somewhat unclear. The present study is noteworthy revealing significant association between some of the cognitive impairments (executive functions and working memory) and particularly social aspect of QoL in patients with schizophrenia.

Conclusions

Quality of life measures are especially important when treating patients with schizophrenia as they provide patients an opportunity to express what is and is not working in their lives. Our results confirm that the cognitive impairments in executive function and working memory appear to have direct impact on the patients' perceived quality of life particularly in social domain which can either be a cause or a consequence of social isolation of patients with schizophrenia. The results of this

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View full text

Is quality of life associated with cognitive impairment in schizophrenia?

Abstract

Background

Methods

Results

Conclusion

Introduction

Section snippets

Patient population and study design

Comparison of quality of life between patient and control groups

Comparison of cognitive functioning between patient and control groups

Relation of quality of life to cognition in patient and control groups

Discussion

Conclusions

Schizophr. Res.

Prog. Neuropsychopharmacol. Biol. Psychiatry

Eur. Psychiatry

Psychiatry Res.

Schizophr. Res.

Neuropsychopharmacology

Eur. Psychiatry

Schizophr. Res.

Diagnostic and Statistical Manual of Mental Disorders

Quality of life in schizophrenia

The generalized pattern of neuropsychological deficits in outpatients with chronic schizophrenia with heterogeneous Wisconsin Card Sorting Test results

Arch. Gen. Psychiatry

Extrapyramidal symptom rating scale

Can. J. Neurol. Sci.

Verbal working memory impairment in schizophrenia patients and their first-degree relatives: evidence from the digit span task

Am. J. Psychiatry

Subjective quality of life in out-patients with schizophrenia: clinical and utilization correlates

Acta Psychiatr. Scand.

Psychometric properties of the WHOQOL-100 and WHOQOL-BREF

J. Psychiatry Psychol. Psychopharmacol.

What are the functional consequences of neurocognitive deficits in schizophrenia?

Am. J. Psychiatry

Neurocognitive deficits and functional outcome in schizophrenia: are we measuring the right stuff?

Schizophr. Bull.

Predictors of subjective quality of life in schizophrenic patients living in the community. A Nordic multicentre study

Int. J. Soc. Psychiatry

Quality of life assessment in people living with psychosis

Soc. Psychiatry Psychiatr. Epidemiol.

The influence of neurocognitive deficits and symptoms on quality of life in schizophrenia

J. Psychiatry Neurosci.