Exploratory study of the association between insight and Theory of Mind (ToM) in stable schizophrenia patients

Abstract

Poor Insight is a common symptom of schizophrenia and it is conceptualised as having at least three principal components, namely unawareness of symptoms, unawareness of the need for treatment, and unawareness of the consequences of the disorder. These deficits have long been of clinical interest and have been shown to predict poorer treatment compliance, clinical outcome, social function, and response to vocational rehabilitation (Amador & David, 2004). Additionally, difficulties to establish and maintain social relationships are core features of schizophrenia, and there is evidence that these may to some extent stem from an alteration of the neural circuits that regulate social behaviour, and in particular deficits in Theory of Mind (ToM) (Lee et al., 2004). <br/>While deficits in insight in schizophrenia have been widely and consistently reported in the literature, evidence on the nature of the ToM dysfunction in this disorder is still controversial. This is mainly due to methodological differences across studies as well as limitations regarding the instruments used for ToM assessment. The first aim of this research consisted of clarifying some of these issues -whether a specific ToM dysfunction existed in schizophrenia and whether this most suitably fitted in the state or trait deficit views- trying to overcome previous methodological drawbacks. We did so by the use of a well matched control group, by controlling for important confounds and by the inclusion of ToM instruments of different nature (verbal and pictorial tasks). Results of this project were included in a first paper (Pousa et al., 2008a) and also led to the publication of a letter discussing part of the conclusions of a recent meta-analysis on ToM in schizophrenia (Pousa, Ruiz & David, 2008). <br/>Following this preliminary work and on the basis of a number of phenomenological parallelisms between insight and ToM dysfunctions that could be appreciated both clinically and in the literature, we decided to explore the relationship between insight and ToM. Given the scarcity of previous studies specifically focused on this issue, the nature of the study was mainly exploratory. The most relevant results of this investigation led to a second paper (Pousa et al., 2008b).<br/>Besides the mentioned publications, two complementary published works are added in the present thesis for their relevance to the project. The first is the manuscript of the Spanish adaptation of the SUMD (Ruiz et al., 2007). The second is a chapter of a book on mental disorders from an evolutionary perspective, titled "Theory of Mind as an evolutionary brain module". This chapter describes the concept of ToM, its measurement, as well as its neurobiological basis and philogenetic development, and was part of the literature review carried out while working on the design of the project (Obiols & Pousa, 2005). <br/>References:<br/>- Amador X & David A. Insight and Psychosis. Awareness of illness in schizophrenia and Related Disorders. (2nd Edition) (2004). Oxford University Press. <br/>- Lee KH; Farrow TFD; Spence SA & Woodruff PWR. (2004) Social cognition, brain networks and schizophrenia. Psychological Medicine 34: 391-400.<br/>- Obiols, JE; Pousa, E. (2005) La Teoría de la Mente como módulo cerebral evolutivo. En J Sanjuan y CJ Cela Conde (Eds) 2005, cap 6, pp105-119. La Profecia de Darwin. Ars Médica. ISBN: 84-9751-090-9<br/>- Pousa, E; Duñó, R; Brébion, G; David, AS; Ruiz, AI; Obiols, JE. (2008a) Theory of mind deficits in chronic schizophrenia: evidence for state dependence. Psychiatry Research, 158: 1-10.<br/>- Pousa, E; Duñó, R; Navarro, B; Ruiz, AI, Obiols, JE; David, AS. (2008b) Exploratory study of the association between insight and Theory of Mind (ToM) in stable schizophrenia patients. Cognitive Neuropsychiatry, 13, 210-232.<br/>- Pousa, E; Ruiz, AI; David, AS. (2008). Mentalising impairment as a trait marker of schizophrenia? Correspondence. British Journal of Psychiatry, 192, 312-315.<br/>- Ruiz, AI; Pousa, E; Duñó, R; Crosas, JM; Cuppa, S; Garcia-Ribera, C. (2008). Adaptación al español de la Escala de Valoración de la No Conciencia de Trastorno Mental SUMD. Actas Españolas de Psiquiatria, 36, 111-118.