Insight into illness, neurocognition and quality of life in schizophrenia

Abstract

Objective

The aim of this study was to assess the impact of insight into illness on self-reported quality of life (QoL) for patients with schizophrenia.

Methods

This cross-sectional study was conducted in the psychiatric department of a French public university teaching hospital. The data collected included socio-demographic information, clinical characteristics, medications, cognitive performance assessments, insight into illness, and the S-QoL 18. A multivariate analysis using multiple linear regressions was performed to determine variables potentially associated with QoL levels.

Results

One hundred and thirteen outpatients with stable schizophrenia were enrolled in our study.

Significant associations were found between QoL and socio-demographic characteristics: a higher QoL was associated with marital status (in couple) and employment. Concerning insight into illness, lower QoL levels were associated with better awareness of the mental disorder, whereas higher QoL levels were associated with better awareness of positive and negative symptoms. Elementary neuropsychological measures were not statistically associated with QoL.

Conclusion

Insight into illness, marital status and employment were the most important features associated with QoL, whereas there was no evidence that elementary neurocognition directly influenced QoL. The different facets of insight into illness should be considered to guide the development of specific interventions intended to improve QoL. Moreover, this study highlights the need for clinicians to pay more attention to the personal impact of schizophrenia, especially upon family life and work.

Introduction

Quality of life (QoL) measurements have become an important way of evaluating the treatments and care provided to patients with schizophrenia (Hofer et al., 2005a, Hofer et al., 2005b). QoL is of the utmost importance to patients and their families, and it encompasses several important dimensions, such as psychological status, functional abilities, personal well-being, social interaction, economic status, vocational status, and physical health (Cramer et al., 2000). Understanding determinants of QoL in schizophrenia is of importance for developing effective interventions that can improve the functional and subjective well-being of patients. However, the determinants of QoL are poorly understood in this population (Tolman and Kurtz, 2010).

Over the last decades, numerous studies have investigated the value of socio-demographic characteristics, psychiatric symptoms, neurocognition, and insight into illness as predictors of QoL (Addington and Addington, 2008, Aksaray et al., 2002, Fitzgerald et al., 2001, Hofer et al., 2005a, Hofer et al., 2005b, Kurtz et al., 2008, Matsui et al., 2008, Prouteau et al., 2005, Woon et al., 2011). However, their results were conflicting because these studies have varied in design, selected characteristics, the sample examined, and the manner in which QoL was defined and measured. Age, gender, educational level, living conditions, and professional status appeared to be potential predictors of QoL (Caron et al., 2005, Folsom et al., 2009, Hofer et al., 2005b, Quercioli et al., 2008, Woon et al., 2011). Several meta-analyses revealed that (1) symptoms, mainly general psychopathology symptoms (e.g., anxiety and depression), have only a modest relationship with QoL (Eack and Newhill, 2007), and (2) neurocognition was largely unrelated to or, for some neurocognitive domains (e.g., speed of processing), negatively related to subjective QoL (Tolman and Kurtz, 2010). Finally, previous studies (Aghababian et al., 2011, Hasson-Ohayon et al., 2006, Kurtz and Tolman, 2010) found that patients with better insight into illness reported a lower QoL. Among the determinants of QoL, insight into illness is particularly relevant because preserved insight has been suggested to be a predictive value for the treatment outcome in schizophrenia, especially when improving adherence to treatment and reducing the risk of relapse and re-hospitalisation (X. F. Amador et al., 1994, Quee et al., 2011). The direction of the relationship between insight and QoL, which can appear paradoxical, should be explored by taking into account the multidimensional aspect of insight and potential confounding factors.

To our knowledge, there no previous study has investigated the impact of insight into illness on QoL in patients with schizophrenia while considering key confounding factors such as neurocognitive functions and socio-demographic characteristics. Only one study has documented the potential impact of insight into illness and elementary neurocognition on QoL (Kurtz and Tolman, 2011). This study found that insight into illness and neurocognition have inverse relationships with QoL. However, in this study, a moderate sample was enrolled (n = 71), insight into illness was measured using the “Lack of Judgment and Insight” item on the Positive and Negative Syndrome Scale (PANSS), the multivariate analysis did not include socio-demographic factors, and, finally, the study used the Satisfaction With Life (SWL) scale, which is a QoL measure not specifically developed for patients with schizophrenia (Test et al., 2005).

The aim of this study was to assess the impact of insight into illness on self-reported QoL in patients with schizophrenia. QoL was measured using a specific QoL questionnaire designed for people with schizophrenia (S-QoL 18) (Boyer et al., 2010), and insight into illness was analysed in its multidimensional aspects (X.F. Amador and Strauss, 1990).