Theory of Mind as a potential trait marker of schizophrenia: a family study

Assessing social cognition in patients with schizophrenia and healthy controls using the reading the mind in the eyes test (RMET): a systematic review and meta-regression

The reading the mind in the eyes test (RMET) - which assesses the theory of mind component of social cognition - is often used to compare social cognition between patients with schizophrenia and healthy controls. There is, however, no systematic review integrating the results of these studies. We identified 198 studies published before July 2020 that administered RMET to patients with schizophrenia or healthy controls from three English-language and two Chinese-language databases. These studies included 41 separate samples of patients with schizophrenia (total n = 1836) and 197 separate samples of healthy controls (total n = 23 675). The pooled RMET score was 19.76 (95% CI 18.91-20.60) in patients and 25.53 (95% CI 25.19-25.87) in controls (z = 12.41, p < 0.001). After excluding small-sample outlier studies, this difference in RMET performance was greater in studies using non-English v. English versions of RMET (Chi [Q] = 8.54, p < 0.001). Meta-regression analyses found a negative association of age with RMET score and a positive association of years of schooling with RMET score in both patients and controls. A secondary meta-analysis using a spline construction of 180 healthy control samples identified a non-monotonic relationship between age and RMET score - RMET scores increased with age before 31 and decreased with age after 31. These results indicate that patients with schizophrenia have substantial deficits in theory of mind compared with healthy controls, supporting the construct validity of RMET as a measure of social cognition. The different results for English versus non-English versions of RMET and the non-monotonic relationship between age and RMET score highlight the importance of the language of administration of RMET and the possibility that the relationship of aging with theory of mind is different from the relationship of aging with other types of cognitive functioning.

Theory of Mind as an endophenotype for schizophrenia spectrum disorder: Study in first episode of psychosis patients and first-degree relatives

BACKGROUND

Deficits in Theory of Mind (ToM) had been suggested as a possible endophenotype for unaffected relatives of first episode of psychosis (FEP) patients. There are a limited number of studies which have evaluated ToM deficits among the siblings and parents of FEP patients.

AIM

This study aimed to explore ToM deficits and its correlates among FEP patients, their siblings, parents, and controls.

METHODOLOGY

FEP patients (N=102), their parents (N=135), siblings (N=97), and controls (N=167) were evaluated on ToM performance with the Reading the Mind in the Eyes Test (Eyes Test). Interview for sociodemographic variables of age, sex, years of education, and IQ estimation and neurocognitive tests were administered to all groups.

RESULTS

FEP patients had a significantly lower performance on the Eyes Test compared to their siblings and controls. However, no significant differences were found between siblings and parents or siblings and controls.

CONCLUSION

Attending our results, we found no evidence for ToM deficits as an endophenotype of SSDs. Furthermore, ToM accuracy may be mediated by interaction with other cognitive domains and play a protective role against psychosis in unaffected siblings.

Social Cognition Impairments in Association to Clinical, Cognitive, Mood, and Fatigue Features in Multiple Sclerosis: A Study Protocol

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system (CNS), characterized by the diffuse grey and white matter damage. Cognitive impairment (CI) is a frequent clinical feature in patients with MS (PwMS) that can be prevalent even in early disease stages, affecting the physical activity and active social participation of PwMS. Limited information is available regarding the influence of MS in social cognition (SC), which may occur independently from the overall neurocognitive dysfunction. In addition, the available information regarding the factors that influence SC in PwMS is limited, e.g., factors such as a patient's physical disability, different cognitive phenotypes, mood status, fatigue. Considering that SC is an important domain of CI in MS and may contribute to subjects' social participation and quality of life, we herein conceptualize and present the methodological design of a cross-sectional study in 100 PwMS of different disease subtypes. The study aims (a) to characterize SC impairment in PwMS in the Greek population and (b) to unveil the relationship between clinical symptoms, phenotypes of CI, mood status and fatigue in PwMS and the potential underlying impairment on tasks of SC.

Disentangling the Relationships Between the Clinical Symptoms of Schizophrenia Spectrum Disorders and Theory of Mind: A Meta-analysis

BACKGROUND AND HYPOTHESIS

Previous studies have suggested links between clinical symptoms and theory of mind (ToM) impairments in schizophrenia spectrum disorders (SSD), but it remains unclear whether some symptoms are more strongly linked to ToM than others.

STUDY DESIGN

A meta-analysis (Prospero; CRD42021259723) was conducted to quantify and compare the strength of the associations between ToM and the clinical symptoms of SSD (Positive, Negative, Cognitive/Disorganization, Depression/Anxiety, Excitability/Hostility). Studies (N = 130, 137 samples) including people with SSD and reporting a correlation between clinical symptoms and ToM were retrieved from Pubmed, PsycNet, Embase, Cochrane Library, Science Direct, Proquest, WorldCat, and Open Gray. Correlations for each dimension and each symptom were entered into a random-effect model using a Fisher's r-to-z transformation and were compared using focused-tests. Publication bias was assessed with the Rosenthal failsafe and by inspecting the funnel plot and the standardized residual histogram.

STUDY RESULTS

The Cognitive/Disorganization (Zr = 0.28) and Negative (Zr = 0.24) dimensions revealed a small to moderate association with ToM, which was significantly stronger than the other dimensions. Within the Cognitive/Disorganization dimension, Difficulty in abstract thinking (Zr = 0.36) and Conceptual disorganization (Zr = 0.39) showed the strongest associations with ToM. The association with the Positive dimension (Zr = 0.16) was small and significantly stronger than the relationship with Depression/Anxiety (Zr = 0.09). Stronger associations were observed between ToM and clinical symptoms in younger patients, those with an earlier age at onset of illness and for tasks assessing a combination of different mental states.

CONCLUSIONS

The relationships between Cognitive/Disorganization, Negative symptoms, and ToM should be considered in treating individuals with SSD.

The effect of sleep disturbance on social cognition in drug-naïve children with attention deficit and hyperactivity disorder

BACKGROUND

A wide variety of psychiatric conditions are associated with social cognitive deficits. The relationship between social cognition and many factors, especially executive functions (EF), has been examined, but there is no study examining sleep and social cognition in children with attention deficit activity disorder (ADHD). It is important to find new approaches and intervention areas to improve their social cognitive skills. The main hypothesis of our study was that sleep disturbance would predict lower social cognition scores. We hypothesized that sleep disturbances and EF impairment could predict lower social cognitive performance.

METHODS

Eighty-five children aged 7-12 years with drug-naïve ADHD were included in the study. Reading the Mind in the Eyes Test (RMET) and Faux Pas Recognition Test (FPRT) were used for social cognition performance; Stroop test was used for executive function performance. Sleep disturbance was evaluated with Children's Sleep Habits Questionnaire (CSHQ), ADHD severity with Conners Parent Rating Scale (CPRS). Hierarchical multiple regression analyses were performed to determine predictive factors of the FPRT and RMET.

RESULTS

Age, gender, and comorbidity were included at step 1, CPRS-RS score was included at step 2, Stroop test part V score was included at step 3, CSHQ total score and sleep duration were included at step 4. Lower sleep disturbance score on CSHQ was associated with higher social cognition FPRT score (p = 0.014). There was no significant relationship between CSHQ and social cognition RMET score. Lower EF score on Stroop test part V was associated with higher social cognition FPRT score (p = 0.002) and higher social cognition RMET score (p < 0.001).

CONCLUSION

These results showed that sleep disturbance and EF are both associated with social cognitive impairment, sleep particularly with the cognitive component. Identifying sleep problems in children with ADHD may provide helpful information in understanding and treating social cognitive impairments. This study is the first to draw attention to the relationship between sleep and social cognition.

Improvement of Theory of Mind in Schizophrenia: A 15-Year Follow-Up Study

Neurocognitive and social cognitive deficits are a hallmark of schizophrenia. The purpose of the present study was to investigate long-term changes in theory of mind (ToM), executive functions, lexical retrieval, and speed of information processing/attention in schizophrenia. We followed-up 31 outpatients with schizophrenia and 31 healthy control subjects for 15 years. ToM was assessed with the Reading the Mind from the Eyes Test (RMET), whereas neurocognitive functions were measured with the verbal fluency (VF) task (executive functions and lexical retrieval) and with the Digit-Symbol Substitution Test (DSST) (speed of information processing/attention). Clinical symptoms and general functioning were rated with the Positive and Negative Syndrome Scale (PANSS) and with the Global Assessment of Functioning (GAF) scale, respectively. At baseline assessment, patients with schizophrenia exhibited significant and generalized impairments on all measures. At follow-up, relative to the baseline, we observed marked improvements in ToM (RMET), stability in executive functions and lexical retrieval (VF), and a significant decline in psychomotor speed/attention (DSST) in schizophrenia. Clinical symptoms and psychosocial functions did not differ at baseline and at follow-up examinations (mild-to-moderate symptoms on the PANSS and moderate difficulty in social and occupational functions on the GAF). These results indicate that patients with schizophrenia with mild-to-moderate symptoms and functional deficits are characterized by improved ToM during over a decade.

Social cognitions in siblings of patients with schizophrenia: a comparison with patients with schizophrenia and healthy controls - a cross-sectional study

BACKGROUND

There are limited number of studies which have evaluated social cognitive deficits among the siblings of patients with schizophrenia.

AIM

This study aimed to evaluate the social cognitive deficits and its correlates among siblings of patients with schizophrenia.

METHODOLOGY

Patients of schizophrenia (N = 34), their siblings (N = 34) and healthy control subjects (N = 31) matched for age, gender, education and intelligence quotient were evaluated on social cognition rating tools in Indian setting (SOCRATIS). Patients were additionally evaluated on Positive and Negative Symptom Scale (PANSS). Siblings were assessed on Comprehensive Assessment for at risk mental state (CAARMS) scale and Short Wisconsin Schizotypy scale. Neurocognitive test battery was applied to all the groups.

RESULTS

Patients with schizophrenia performed the worst and the healthy controls performed the best, with siblings falling intermediate on all the subtests of social cognition (except for externalizing bias and personalized bias) and neurocognition. There were negative correlation between some of the domains of social cognition and various domains of CAARMS. Higher level of schizotypy was associated with higher level of social cognitive deficits.

CONCLUSION

Social cognitive deficits can act as an important endophenotype for estimating the risk of schizophrenia in at risk siblings. Further, social cognitive deficits must be considered as important target for intervention among the at risk siblings to improve their outcome.

Cognitive Correlates of Different Mentalizing Abilities in Individuals with High and Low Trait Schizotypy: Findings from an Extreme-Group Design

Mentalizing or Theory of Mind (ToM) deficits in schizophrenia have been studied to great extent, but studies involving samples of trait schizotypy yield ambiguous results. Executive functions like cognitive inhibition, cognitive flexibility, and agency are all prerequisites of mentalizing, and it is assumed that the impairment of these functions contributes to ToM deficits in schizophrenia. Whether these impairments influence the ToM performance of people with high trait schizotypy remains unclear. Although impaired self-agency has repeatedly been identified in people with schizotypy, its role in mentalizing is yet to be investigated. The main aim of this study was to explore whether deficits in cognitive and affective ToM can be found in high trait schizotypy, and to identify in what way these deficits are related to the positive and negative dimensions of schizotypy. The secondary aim was to examine whether these deficits correlate with executive functions. Based on the dimensional view of the schizophrenia spectrum, an extreme-group design was applied to non-clinical volunteers demonstrating high (N = 39) and low (N = 47) trait schizotypy. Affective and cognitive ToM were investigated using the Movie for Assessment of Social Cognition, a sensitive and video-based measurement. Cognitive inhibition was assessed using the Stroop Test, and cognitive flexibility was analyzed using the Trail-Making Test. Agency was measured using a computerized self-agency paradigm. Participants in the high-schizotypy group performed significantly worse in the affective ToM task (d = 0.79), and their overall ToM performance was significantly impaired (d = 0.60). No between-group differences were found with regards to cognitive ToM, executive functions, and self-agency. Cognitive flexibility correlated negatively with positive schizotypy, and contributed to a worse overall and affective ToM. Impaired cognitive inhibition contributed to undermentalizing-type errors. It was found that non-clinical participants with high trait (positive) schizotypy - especially those with slight executive-function deficits - may have difficulties in understanding the emotional state of others and consequently in functioning in social situations.

Evidence for Trait Related Theory of Mind Impairment in First Episode Psychosis Patients and Its Relationship with Processing Speed: A 3 Year Follow-up Study

This study aimed to confirm whether first-episode psychosis patients present a stable trait impairment in theory of mind (ToM) and to examine the potential relationship between ToM and clinical symptomatology and neurocognition. Patients with a first episode of psychosis (N = 160) and healthy controls (N = 159) were assessed with an extensive neuropsychological test battery, which included a mental state decoding task known as “The Reading the Mind in the Eyes” (Eyes test), at baseline and reassessed after 1 and 3 years. The clinical group performed below healthy controls on the Eyes test while not showing test-retest differences between baseline and follow-up administrations. Analyses revealed age, education and premorbid IQ as potential moderators. Poorer performance on the Eyes test was not linked to clinical symptomatology but was associated with greater neurocognitive deficit, particularly related to processing speed. The persistence of ToM deficits in patients suggests that there are trait related metalizing impairments in first episode psychosis. This study shows the influence of processing speed and moderator variables on efficient ToM.

Theory of mind reasoning in schizophrenia patients and non-psychotic relatives

Research consistently demonstrates that schizophrenia patients have theory of mind (ToM) impairments. Additionally, there is some evidence that family members of schizophrenia patients also demonstrate impairments in ToM, suggesting a genetic vulnerability for the disorder. This study assessed ToM abilities (i.e., sarcasm comprehension) in schizophrenia patients and their first-degree biological relatives during video-taped social interactions, to be representative of real-world interactions and to assess for disease-specific and/or genetic liability effects. Additionally, we assessed whether ToM abilities predicted social and global functioning in schizophrenia patients, and whether symptoms were associated with ToM deficits. Schizophrenia patients demonstrated impairments in sarcasm comprehension compared to controls and relatives, whereas relatives showed intact comprehension. Symptoms of schizophrenia significantly predicted worse ToM abilities. Furthermore, in schizophrenia patients, impaired ToM reasoning predicted worse social and global functioning. Given schizophrenia patients demonstrated impairments in ToM reasoning in a task that resembles real-life interactions, this might be a key area for remediation.

Bridging disparate symptoms of schizophrenia: a triple network dysfunction theory

Schizophrenia is a complex neuropsychiatric disorder with variable symptomatology, traditionally divided into positive and negative symptoms, and cognitive deficits. However, the etiology of this disorder has yet to be fully understood. Recent findings suggest that alteration of the basic sense of self-awareness may be an essential distortion of schizophrenia spectrum disorders. In addition, extensive research of social and mentalizing abilities has stressed the role of distortion of social skills in schizophrenia.This article aims to propose and support a concept of a triple brain network model of the dysfunctional switching between default mode and central executive network (CEN) related to the aberrant activity of the salience network. This model could represent a unitary mechanism of a wide array of symptom domains present in schizophrenia including the deficit of self (self-awareness and self-representation) and theory of mind (ToM) dysfunctions along with the traditional positive, negative and cognitive domains. We review previous studies which document the dysfunctions of self and ToM in schizophrenia together with neuroimaging data that support the triple brain network model as a common neuronal substrate of this dysfunction.

Theory of mind impairments in patients with deficit schizophrenia

The deficit syndrome, a subgroup within schizophrenia, is characterized by enduring, idiopathic negative symptoms. Theory of mind (ToM), a domain of social cognition, is the ability of attributing mental states to ourselves and other people. ToM impairments have not been investigated earlier in deficit schizophrenia. The aim of the present study was to examine ToM differences between patients with deficit (SZ-D) and non-deficit schizophrenia (SZ-ND). Gender differences were also investigated, and based on the literature a better ToM performance was expected in female patients. The participants were 28 patients with SZ-ND, 30 patients with SZ-D, and 29 healthy control volunteers. The "Reading the Mind in the Eyes Test" was used to asses ToM deficits. Control subjects outperformed both patient groups, while there were no significant differences between the two schizophrenia subgroups. In female subjects, both controls and patients with SZ-ND performed significantly better than the SZ-D subgroup. In male subjects, controls performed significantly better than both patient groups. The "diminished emotional range" and the "curbing of interest" items of the Schedule for the Deficit Syndrome showed significant negative relationship with the ToM score. Our main finding is that female subjects with SZ-ND performed significantly better than female subjects with SZ-D.

Mentalizing functions provide a conceptual link of brain function and social cognition in major mental disorders

The review presents a research perspective that defines mentalizing functions as a very promising topic to bridge psychopathology and neurobiological foundations of mental disorders. However, the high diversity of existing observations in mentalizing research calls for a structured assessment of functional mentalizing subdomains. A notable problem is the overlap of functional systems involved in mentalizing and emotion processing. A proposed solution is to conceptualize mentalizing functions due to their content (visuospatial vs. emotional) perspective and substrates (cognitive or explicit signals). This conceptual organization is mirrored in functional imaging experiments dissociating anteromedial and posterolateral brain regions, especially the involvement of the medial prefrontal cortex in mentalizing emotions and the temporoparietal cortex in visuospatial perspective taking. The present state and perspectives of mentalizing research are demonstrated in two major fields of mental disorders, depression and schizophrenia. In depression the existent contradictory findings demand a control of cognitive impairments, which are frequently associated with depressive disorders. In schizophrenia there is already consistent evidence that defines mentalizing functions as promising endophenotype, which can possibly link psychopathology to its neurobiological foundations.

Theory of mind impairments in first-episode psychosis, individuals at ultra-high risk for psychosis and in first-degree relatives of schizophrenia: systematic review and meta-analysis

Theory of mind (ToM) deficit is a well-established feature of schizophrenia and has been suggested as a vulnerability marker of this disorder. However, as most of this evidence is based on studies in chronic patients, it is less clear whether ToM is impaired prior to or following the onset of a first-episode and whether it is evident in unaffected relatives of patients. In this meta-analysis, ToM performance of 3005 individuals with first-episode psychosis (FEP), individuals at ultra-high risk for psychosis (UHR) and unaffected relatives were compared with 1351 healthy controls. ToM was substantially impaired in first-episode psychosis (Cohen d=1.0) and this deficit was comparable to findings in chronic patients. ToM was also impaired in unaffected relatives (d=0.37) and UHR subjects (d=0.45) and performances of these groups were intermediate between FES and healthy controls. Severity of ToM deficits in unaffected relatives and UHR subjects was similar to other cognitive deficits observed in these groups. Longitudinal studies of clinical and genetic high-risk subjects are necessary to investigate the trajectory of development of ToM deficits in schizophrenia.

Psychiatric comorbidities in asperger syndrome and high functioning autism: diagnostic challenges

Several psychiatric conditions, both internalizing and externalizing, have been documented in comorbidity with Asperger Syndrome (AS) and High Functioning Autism (HFA). In this review we examine the interplay between psychiatric comorbidities and AS/HFA. In particular, we will focus our attention on three main issues. First, we examine which psychiatric disorders are more frequently associated with AS/HFA. Second, we review which diagnostic tools are currently available for clinicians to investigate and diagnose the associated psychiatric disorders in individuals with AS/HFA. Third, we discuss the challenges that clinicians and researchers face in trying to determine whether the psychiatric symptoms are phenotypic manifestations of AS/HFA or rather they are the expression of a distinct, though comorbid, disorder. We will also consider the role played by the environment in the manifestation and interpretation of these symptoms. Finally, we will propose some strategies to try to address these issues, and we will discuss therapeutic implications.