Theory of mind deficits in chronic schizophrenia: evidence for state dependence

There is evidence that people with schizophrenia show specific deficits in theory of mind (ToM). However, it is a matter of debate whether these are trait or state dependent, and the nature of the relationship between ToM deficits and particular symptoms is controversial. This study aimed to shed further light on these issues by (1) examining ToM abilities in 61 individuals with chronic schizophrenia during a stable phase as compared with 51 healthy controls matched by gender, age, educational level and current IQ, and (2) exploring the relationship between ToM and symptoms. Second order verbal stories and a non-verbal picture-sequencing task were used as ToM measures. Results showed no differences in ToM performance between patients and controls on either measure. Subsequent subgrouping of patients into remitted and non-remitted showed a worse performance of non-remitted patients only on second order ToM tasks. Specific ToM deficits were found associated with delusions. Association with negative symptoms was found to be less specific and accounted for by illness chronicity and general cognitive impairment. The results from the present study are in line with models which hypothesise that specific ToM deficits in schizophrenia are state dependent and associated with delusions. Such associations may also be task specific.     

Different aspects of theory of mind in paranoid schizophrenia: evidence from a video-based assessment

In schizophrenia, impairments of theory of mind (ToM) may be due to excessive ('overmentalizing') or defective ('undermentalizing') attribution of mental states. However, most ToM tests differentiate neither between 'overmentalizing' and 'undermentalizing' nor between cognitive and affective ToM in schizophrenia. This study aimed at differentiating these aspects of ToM in 80 patients diagnosed with paranoid schizophrenia and 80 matched healthy controls using the 'Movie for the Assessment of Social Cognition' (MASC). Outcome parameters comprised 1) error counts representing 'undermentalizing' or 'overmentalizing', 2) decoding of cognitive or emotional mental states and 3) non-social inferencing. Multivariate analysis of covariance (MANCOVA) showed significantly abnormal scores for two dimensions of 'undermentalizing' as well as for cognitive and emotional ToM that were not explained by global cognitive deficits. Scores for 'overmentalizing' did not differ between groups, when age, gender, non-social reasoning and memory were controlled. In schizophrenic patients, negative symptoms were associated with a lack of a mental state concept, while positive symptoms like delusions were associated with 'overmentalizing', supporting respective etiological concepts of delusions.     

Insights into theory of mind in schizophrenia: the impact of cognitive impairment

The ability to mentalize and attribute beliefs, intentions and desires to others has been found by the vast majority of studies to be impaired in patients with schizophrenia. However, it is not yet clear if this deficit in Theory of Mind (ToM) is independent of their also well established deficits in basic cognitive functioning. In the present study, we sought to clarify the above relationship by exploring patients' ToM impairment after controlling for their putative cognitive deficits. We examined 36 patients with schizophrenia and 30 healthy matched controls on first and second order tasks of ToM and on commonly used neuropsychological tests. Patients performed poorly on ToM tasks even after controlling for their cognitive deficits, particularly on second order ToM. The present findings contribute to the understanding of the mechanism of ToM, suggesting that ToM deficits are core characteristics in schizophrenia and relatively independent of patients' cognitive impairment.     

Theory of mind impairment: a distinct trait‐marker for schizophrenia spectrum disorders and bipolar disorder?

Objective: The aim of this study was to critically review the literature in order to determine if Theory of Mind (ToM) impairment can be considered a trait‐marker for schizophrenia spectrum disorders and bipolar disorder (BD). Method: After a thorough literature search, we reviewed the empirical studies investigating ToM impairments in remitted schizophrenia patients, first episode patients, subjects at high‐risk (HR) for psychosis and first‐degree relatives of schizophrenia patients. Studies investigating ToM impairment in other schizophrenia spectrum conditions, affective psychosis and BD were also reviewed. Results: ToM abnormalities exist at onset and continue throughout the course of schizophrenia, persist into remission, and while less severe, are apparent in HR populations. Mentalizing impairments are also observed in other forms of psychotic illness and BD. Conclusion: Mentalizing impairment in schizophrenia spectrum disorders and BD might reflect underlying general cognitive deficits and residual symptom expression, rather than representing a specific trait‐marker.     

A closer look at the relationship between the subdomains of social functioning,social cognition and symptomatology in clinically stable patients with schizophrenia

Impairments in social functioning commonly seen in schizophrenia are thought to be mediated by deficits in the domains of social cognition. Some previous research has explored how social cognitive skills and psychotic symptoms are associated with social functioning, however these associations are still under debate. The main aim of this study was to investigate the relationship between different domains of social cognition and psychotic symptomatology, and also to look at the relationships with individual subdomains of social functioning within a clinically stable schizophrenia population. 45 outpatients were recruited and symptoms were assessed with the PANSS, and measures of emotion processing, affective and cognitive theory of mind (ToM), mental state reasoning attributional biases, and social functioning were taken. A correlational analysis was performed with the data. Following this, a regression analysis was used to reveal which domains of social cognition best predicted psychotic symptoms. In this stable group of patients, our results support the suggestion of a likely distinction between affective and cognitive components of ToM. The study also demonstrated that ToM and mental state reasoning were the best predictors of psychotic symptoms. Here we reveal that cognitive ToM had the most widespread relationship with social functioning, across multiple subdomains, while only some specific subdomains of social functioning correlated with other domains of social cognition and symptomatology. Further to this, positive symptoms were associated with much fewer subdomains of social functioning than negative and general symptoms. These findings imply that different aspects of social functioning may be served by different domains of social cognition and symptomatology.     

Naive theory impairment in schizophrenia: is it domain-specific?

The ability to represent mental states of self and others to account for behavior is called theory of mind (ToM). This study examined whether ToM deficit in schizophrenia patients is a specific deficit in the cognitive component of interpersonal skills or a more global deficit, involving impaired information processing skills. Schizophrenia inpatients (N = 41) were compared with a control group of healthy subjects (N = 22) and to nonschizophrenia psychiatric patients (24 with affective disorders, seven with other psychosis) over a range of ToM tasks and another naive theory (theory of biology; ToB). Psychiatric inpatients as a whole showed significant deficit compared with the control group of healthy subjects in ToM tasks. The schizophrenia patients showed significantly larger deficits compared with patients suffering from affective disorder, while the performance of patients with nonschizophrenia psychosis was intermediate. In contrast, no difference was observed in the performance of the different groups on the ToB tasks. The fact that a deficit was found in ToM but not in ToB suggests a specific deficit in a cognitive component of interpersonal skills in schizophrenia rather than a general deficit in information processing skills. Naive theories deficits in schizophrenia seem to be domain-dependent.     

The relationship between insight and theory of mind in schizophrenia

IntroductionIt has been proposed that theory of mind (ToM) deficits underlying difficulties in taking the perspective of others may substantially contribute to insight impairment in schizophrenia. The present study aimed to explore the effect of ToM deficits on insight impairment independently of co-existent neurocognitive deficits and symptom severity in chronic schizophrenia.MethodsFifty-eight chronic patients with schizophrenia and 56 matched healthy participants were assessed with the Schedule for the Assessment of Insight (SAI–E) along with a series of ToM tasks and a comprehensive battery of neuropsychological measures. Symptoms were measured with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia.ResultsToM impairment explained a substantial proportion of variance in overall insight and its three major components: awareness of illness, relabelling of symptoms and treatment compliance. Moreover, the effect of ToM deficits on insight remained significant even after controlling for all neurocognitive factors and symptom ratings. Regression analysis showed that symptoms and cognitive deficits also contribute to impaired insight in schizophrenia. General intellectual ability was negatively associated with both overall insight and relabelling of symptoms. Executive functions were negatively associated with relabelling.ConclusionOur findings confirm that ToM deficits negatively affect insight independently of neurocognitive deficits and symptom severity in chronic schizophrenia. The effect of ToM deficits on insight should be further examined in the broader context of the failures in metacognition and their relationships with insight impairment in schizophrenia.     

Metacognition in schizophrenia: Correlates and stability of deficits in theory of mind and self-reflectivity

Research suggests that many with schizophrenia experience a range of deficits in metacognition including difficulties recognizing the emotions and intentions of others as well as reflecting upon and questioning their own thinking. Unclear, however, is the extent to which these deficits are stable over time, how closely related they are to one another and whether their associations with core aspects of the disorder such as disorganization symptoms are stable over time. To explore this issue, we administered three assessments of Theory of Mind (ToM), the Beck Cognitive Insight Scale (BCIS), and the Positive and Negative Syndrome Scale at baseline and 6 months to 36 participants with schizophrenia. Correlations revealed the ToM and BCIS scores were stable across the two test administrations and that the ToM tests were closely linked to each other but not to the BCIS. Poorer baseline performance on the ToM tests and the Self-Certainty scale of the BCIS were linked to greater cognitive symptoms at baseline and follow-up, while greater Self-Reflectivity on the BCIS was linked to greater levels of emotional distress at both baseline and 6-month follow-up. Results are consistent with assertions that deficits in metacognition are a stable feature of schizophrenia.     

Theory of mind in schizophrenia: The role of clinical symptomatology and neurocognition in understanding other people's thoughts and intentions

A wealth of studies has demonstrated that patients with schizophrenia are impaired in “theory of mind” (ToM). Here, we used a novel five-factor model of the Positive and Negative Syndrome Scale (PANSS) to test the hypothesis that selectivity of ToM deficits in schizophrenia depends on the predominating symptoms. We predicted that ToM impairments would be non-selective in patients with pronounced negative (NF) or disorganized symptoms (DF), whereas selective ToM impairment would occur in patients with predominant positive symptoms (PF). We recruited 50 patients diagnosed with schizophrenia or schizoaffective disorder and examined premorbid intelligence, executive functioning, ToM and psychopathology in comparison to a group of 29 healthy controls. Compared with healthy controls, patients performed more poorly on tasks involving executive functioning and ToM abilities. Using a novel PANSS five-factor model, we found a significant association of ToM deficits with the “disorganization” factor. Moreover, several individual PANSS items that were included within the disorganization factor correlated with impaired ToM, albeit the majority of correlations disappeared when controlled for executive functioning, and, to a lesser degree, when controlled for IQ. In addition, in the patient group we found interactions of poor ToM with symptoms belonging to the “emotional distress” factor of the PANSS. Contrary to expectations, associations of impaired ToM with positive symptoms were absent, and poor with regards to negative symptoms. This study lends further support to the assumption of differential associations of ToM deficits with individual symptoms and symptom clusters in schizophrenia.     

Lateralized cognitive dysfunction and psychotic symptoms in schizophrenia

Our understanding of hemispheric asymmetries in schizophrenia can be attributed to extensive neuropsychological and neuroimaging research on this topic; however, it has yet to be determined whether lateralized cognitive dysfunction represents a single core trait in schizophrenia or whether the lateralized impairments are domain specific. To test whether lateralized deficits are core features in schizophrenia we examined performance across a wide range of lateralized cognitive domains including attention, fluency, recognition memory, perception, and arousal. We also examined the relationship between lateralized impairments and psychotic and affective symptoms to determine whether abnormal hemispheric asymmetries were possibly state-related. The sample consisted of 43 subjects with schizophrenia and 66 normal healthy comparison subjects without psychiatric illness. Schizophrenia subjects exhibited abnormal right hemisphere performance on a test of recognition memory and abnormal left hemisphere performance on a measure of arousal. These findings suggest that lateralized cognitive disturbances in schizophrenia do not represent a single core lateralized deficit. Regarding the symptom analyses, severity of positive symptoms was related to right hemisphere cognitive impairment (including fluency and recognition memory), whereas severity of negative symptoms was related to left hemisphere cognitive impairment (including fluency). Overall, our findings suggest that lateralized dysfunction can occur in both hemispheres in schizophrenia, and that the positive psychotic symptoms may relate more to right hemisphere impairment, whereas negative psychotic symptoms may related more to left hemisphere impairment.     

Risperidone,negative symptoms and cognitive deficit in schizophrenia: an open study

The aim of this study was to evaluate the effects of a new antipsychotic compound on negative symptoms and cognitive deficit in schizophrenia. Psychiatric symptoms and cognition were assessed in 25 patients with schizophrenia, at baseline and after they had taken risperidone for 4 weeks. The Positive and Negative Symptoms Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and two WAIS sub-tests were used to assess the patients. After the study period, both negative and positive symptoms and also measures of cognitive performance improved significantly. The WCST results correlated with negative symptom scores before and after treatment. This suggests that negative symptoms and cognitive deficit have a common underlying substrate which is the target of the risperidone treatment. Our data show that risperidone may have a substantial effect on complex cognitive functions in schizophrenia, and they suggest that certain cognitive deficits are relatively dependent on the negative symptoms of this disorder.     

Putting things into perspective: the nature and impact of theory of mind impairment in Huntington’s disease

In Huntington’s disease (HD), frontostriatal dysfunction may lead to deficits in theory of mind (ToM), in addition to broader cognitive impairment. We investigated relationships between patients’ spatial and social perspective taking performance and executive deficits, self-reported everyday perspective taking, motor symptoms, functional capacity and quality of life. Thirty patients with symptomatic HD and twenty-three healthy controls of similar age and education completed two ToM tasks, a scale assessing everyday interpersonal perspective taking, a novel object-based spatial perspective taking task (SPT) and executive measures. Ratings of quality of life, psychiatric symptoms, motor symptom severity and functional capacity were also taken for patients. When compared to controls, patients exhibited significant deficits in ToM and spatial perspective taking and lower everyday perspective taking scores. Executive deficits were linked to poor understanding of socially inappropriate remarks and errors in mental state attribution. This may be the first study to show that aspects of ToM performance are linked to spatial perspective taking, motor symptom severity and functional capacity in HD. Our findings indicate that patients with HD exhibit evidence of reduced perspective taking in everyday life in addition to poor performance on social and SPTs. They also emphasise the need to better specify the precise cognitive and neural bases for ToM deficits in neurodegenerative conditions. Further research exploring the impact of striatal degeneration on perspective taking abilities will make a valuable contribution to the continued development of functional models of frontostriatal circuitry.     

Poor premorbid social functioning and theory of mind deficit in schizophrenia: evidence of reduced context processing?

Investigations have demonstrated deficits in theory of mind (ToM) ability in schizophrenia. Yet, the development of, and mechanisms associated with these deficits are not well understood. The present investigation examined the hypothesis that, among chronic schizophrenia patients, impaired ToM is associated with failures in context processing, greater disorganized symptoms, and poor premorbid functioning. Forty-two inpatients with schizophrenia spectrum disorders were assessed on tests of ToM, visual and linguistic context processing, executive functioning, and verbal IQ. Symptomatology and premorbid functioning were also assessed. Results revealed that more impaired ToM was associated with poorer performance on both visual and linguistic context processing measures and higher ratings of disorganization on the BRRS. ToM was also associated with poorer childhood social functioning and an earlier age of illness onset. ToM was not associated with verbal processing speed, verbal fluency, response inhibition, sequence learning, or estimated verbal IQ. A significant regression model including measures of childhood peer problems and visual and language context processing significantly predicted ToM performance and accounted for 43% of the variance. These findings suggest that, among chronic schizophrenia patients, deficits in ToM ability may be the result of context processing impairments. These impairments may be a factor in both poor social functioning during childhood and greater disorganized symptoms after illness onset.     

Impaired verbal source monitoring in schizophrenia: An intermediate trait vulnerability marker?

Patients with schizophrenia, particularly those with positive symptoms show impaired verbal source monitoring. Specific cognitive deficits have been observed during both active and remission phases of the illness as well as in groups of unaffected first degree relatives of patients with schizophrenia. This type of schizophrenia vulnerability marker may precede the onset of frank psychotic symptoms and contribute to their developments. The aim of this study was first to determine if unaffected siblings were impaired in discriminate internal vs. external generated events when compared to their remitted schizophrenics relatives and healthy subjects. Performances of healthy subjects were then compared with results from previous studies with acute hallucinating patients, acute non-hallucinating patients and patients with resistant auditory verbal hallucinations. Compared with healthy subjects, unaffected siblings are impaired (effect size, ES=0.7), remitted or acute non-hallucinating patients are more impaired than siblings (ES=1.4); patients with verbal auditory hallucinations (acute or resistant) are even more impaired than non-hallucinating patients (ES=2.1). Our results suggest that a source monitoring deficit could be considered as an intermediate vulnerability marker of schizophrenia.     

Theory of mind deficit in bipolar disorder: is it related to a previous history of psychotic symptoms?

It has been hypothesized that a Theory of Mind (ToM) deficit could be a vulnerability marker for psychosis. Recent studies, however, have shown ToM deficits in affective relapses of bipolar disorder as well as in the euthymic phase. This study analyzes the relationship between ToM and a previous history of psychotic symptoms in bipolar disorder. ToM, sustained attention and executive functions were analyzed in 75 bipolar euthymic patients with three or more previous relapses (42 of them had a history of psychotic symptoms and 33 did not) and 48 healthy subjects. ToM was assessed with the Advanced Test by Happé. ToM performance was similar in bipolar patients with or without a history of psychotic symptoms, and in both cases it was significantly reduced as compared with the healthy control group. Similarly, both bipolar groups showed impaired sustained attention and executive functions. This general cognitive deficit partially explains the differences obtained in ToM. The ToM instrument used shows low sensitivity for assessing ToM in bipolar patients and it could partially reflect general cognitive functioning rather than a specific deficit in psychosis. ToM deficit is not a trait marker for psychosis, given that it is present in bipolar disorder regardless of a previous history of psychotic symptoms.     

Theory of mind functioning in mentally disordered offenders detained in high security psychiatric care: its relationship to clinical outcome, need and risk

BACKGROUND: Theory of mind (ToM) refers to the cognitive mechanisms that allow us to infer our own mental states and those of others. Whilst ToM deficits are frequently observed among individuals with schizophrenia, little is known about their relationship to functional outcome. AIMS: Among patients with schizophrenia in a high security hospital, to test whether ToM performance, in relation to other cognitive and clinical variables, is related to measures of subsequent clinical outcome. METHODS: ToM was assessed using the modified advanced test (MAT) and the revised eyes task (RET). Outcome, including ongoing need and risk, was assessed using the HoNOS secure, CANFOR and HCR-20 respectively three years post ToM assessment. RESULTS: Performance on the RET was the only variable to be significantly correlated with the symptom ratings of the HoNOS secure and the HCR-20 total scores. Performance on the RET also accounted for approximately half of the variance in the CANFOR ratings and a third in the risk management item ratings of the HCR-20. Age, number of years diagnosed with schizophrenia and other aspects of cognition were also significantly correlated with the HoNOS security scale. CONCLUSIONS: The results suggest that social perceptual ToM may be a useful prognostic indicator, but also that ToM impairments may represent an unmet need. Replication of the work with larger and more diverse samples of people with schizophrenia is necessary, as well as trials of therapeutic effort directed at improvement of ToM impairments.     

State-dependent implicit learning deficit in schizophrenia: evidence from 20-month follow-up

Previous research has confirmed stable explicit memory deficits in schizophrenia across disease states. However, little is known about the implicit learning capabilities of individuals with schizophrenia across the course of illness. The current study assessed procedural learning in 19 schizophrenia subjects (DSM-IV criteria) and 19 matched controls using the Serial Reaction-Time Task (SRTT). The severity of negative, positive and disorganized symptoms was assessed using the Scales for the Assessment of Positive and Negative Symptoms. A sub-sample of 11 schizophrenia subjects and 11 controls was reassessed 20 months later when symptoms in the schizophrenia subjects had largely remitted. Schizophrenia subjects were severely impaired on sequence-specific procedural learning during an acute episode. This deficit could not be explained by a general memory or processing speed impairment. Impaired implicit learning scores were significantly related to higher ratings of disorganized symptoms. However, 20 months later, when acute symptoms had remitted, the performance of the schizophrenia subjects on procedural learning had normalized. Our findings might share a conceptual overlap with previous reports of a reduced ability of schizophrenia subjects during an acute episode to adapt ongoing perceptual and behavioral programs to previously experienced regularities in their environment.     

Theory of mind in schizophrenia: clinical aspects and empirical research

The term Theory of Mind (ToM) refers to the capacity to infer one's own and other persons' mental states. A substantial body of research has highlighted impaired ToM in a variety of neuropsychiatric disorders, including schizophrenia. There is good empirical evidence that ToM is specifically impaired in schizophrenia and that many psychotic symptoms--for instance, delusions of alien control and persecution--may best be understood in light of a disturbed capacity in patients to relate their own intentions to executing behavior, and to monitor others' intentions. However, it is still under debate if impaired ToM in schizophrenia is a state- or trait marker and whether patients could benefit from cognitive training in this domain. Recently, research has not only emphasized social cognitive deficits in patients, but has also focussed on interactions between ToM with language and other cognitive functions. Furthermore, interest in subprocesses of social cognition in psychotic spectrum disorders (e. g. schizotypy) is growing. The aim of this article is to line out clinical aspects of disturbed social cognition, to clarify terms used in this context as well as to present the latest research approaches into social cognition deficits.     

Cognitive and functional changes with aging in schizophrenia.

The variation in functional outcome in schizophrenia appears to be exaggerated in late life. The cognitive and functional deficits commonly seen in younger schizophrenic patients appear to worsen in some cases in late life, while others patients appear to have a stable course of illness without functional decline, and still other patients have been reported to have essentially no residual symptoms in their later years. Cognitive and functional deficits appear to worsen more significantly in patients with a lifetime course of severe functional deficit. Despite the profound functional and cognitive deficits in these patients, neuropathologic studies have found no evidence of typical causes of severe cognitive impairments. This paper reviews the current findings on cognitive and functional changes in aging in schizophrenia, with a specific focus on patients with a poor lifetime functional outcome.     

Self-rated and performance-based empathy in schizophrenia: The impact of cognitive deficits

People may be much less empathic than they think they are. It is not clear whether patients with schizophrenia who have impaired empathic abilities also exhibit diminished ability to accurately appraise their own such skills. The present study aimed to examine: (a) the accuracy of self-appraisal of empathy and (b) the impact of specific cognitive functions on both self-rated and performance-based empathy in schizophrenia patients and healthy volunteers. Self-reported empathy and performance-based empathy were assessed in 52 chronic patients with schizophrenia and 45 matched healthy participants with the empathy quotient and the empathy score in the Faux Pas test, respectively. Neuropsychological functioning and symptom severity were also assessed. No significant correlations between self-reported and performance-based empathy scores were found in patients, whereas these correlations were significant and positive in the control group, with the exception of Faux Pas recognition. Cognitive deficits, specifically in processing speed and theory of mind, negatively affected performance-based but not self-rated empathy in schizophrenia. Patients with less negative and more positive symptoms and lower set shifting ability reported higher empathic abilities. Self-reported empathy and empathic abilities do not show a simple relationship. Our findings highlight a double deficit related to empathic responding in schizophrenia: diminished performance associated with cognitive deficits and inaccurate self-appraisal of empathic abilities.