From Social Cognition to Negative Symptoms in Schizophrenia: How Do We Get There From Here?

Repetitive transcranial magnetic stimulation can improve negative symptoms and/or neurocognitive impairments in the first psychosis episode: A randomized controlled trial

OBJECTIVE

Negative symptoms and neurocognitive impairments in psychosis correlate with their severity. Currently, there is no satisfactory treatment. We aimed to evaluate and compare the effects of repetitive transcranial magnetic stimulation(rTMS) on negative symptoms and neurocognitive impairments in patients in first-episode of psychosis(FEP) in a randomized controlled trial(RCT).

METHOD

This is a single-site RCT of 85 patients with FEP. Patients were randomized to receive a 4-week course of active(n = 45) or sham rTMS(n = 40). Factor analysis was applied to a cross-sectional dataset of 744 FEP patients who completed negative symptom evaluation and neurocognitive battery tests. Two independent dimensions were generated and used for the K-means cluster analysis to produce sub-clusters. rTMS of 1-Hz was delivered to the right orbitofrontal(OFC) cortex.

RESULTS

Two distinct dimensional factors of neurocognitive functions(factor-1) and negative symptoms(factor-2), and three clusters with distinctive features were generated. Significant improvements in factor-1 and factor-2 were observed after 4-weeks of rTMS treatment in both the active and sham rTMS groups. The repeated-measures analysis of variance revealed a significant effect of time×group(F = 5.594, p = 0.021, η2 = 0.073) on factor-2, but no effect of time×group on factor-1. Only improvements in negative symptoms were significantly different between the active and sham rTMS groups(p = 0.028). Patients in cluster-3 characterized by extensive negative symptoms, showed greater improvement in the active rTMS group than in the sham rTMS group.

CONCLUSIONS

The 1-Hz right OFC cortex rTMS is more effective in reducing negative symptoms than neurocognitive impairments. It is especially effective in patients with dominantly negative symptoms in FEP.

The social cognitive and neural mechanisms that underlie social functioning in individuals with schizophrenia - a review

In many individuals with a diagnosis of schizophrenia social functioning is impaired across the lifespan. Social cognition has emerged as one of the possible factors that may contribute to these challenges. Neuroimaging research can give further insights into the underlying mechanisms of social (cognitive) difficulties. This review summarises the evidence on the associations between social cognition in the domains of theory of mind and emotion perception and processing, and individuals' social functioning and social skills, as well as associated neural mechanisms. Eighteen behavioural studies were conducted since the last major review and meta-analysis in the field (inclusion between 7/2017 and 1/2022). No major review has investigated the link between the neural mechanisms of social cognition and their association with social functioning in schizophrenia. Fourteen relevant studies were included (from 1/2000 to 1/2022). The findings of the behavioural studies showed that associations with social outcomes were slightly stronger for theory of mind than for emotion perception and processing. Moreover, performance in both social cognitive domains was more strongly associated with performance on social skill measures than questionnaire-based assessment of social functioning in the community. Studies on the underlying neural substrate of these associations presented mixed findings. In general, higher activation in various regions of the social brain was associated with better social functioning. The available evidence suggests some shared regions that might underlie the social cognition-social outcome link between different domains. However, due to the heterogeneity in approaches and findings, the current knowledge base will need to be expanded before firm conclusions can be drawn.

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.

Autobiographical memory and the self on the psychosis continuum: investigating their relationship with positive- and negative-like symptoms

Autobiographical memory is severely impaired in schizophrenia, but previous work has largely treated both as unitary concepts. Here, we examined how various dimensions of autobiographical memory relate to different aspects of psychosis. Participants were recruited from the general population (Study 1, N = 264) and a university subject pool (Study 2, N = 305). We examined different measures of autobiographical memory and self (i.e., involuntary memory, autobiographical recollection, self-knowledge and self-awareness), at the trait level in Study 1 and both trait and state levels in Study 2, as a function of positive-and negative-like symptoms of psychosis. Across both studies, positive and negative dimensions of psychosis were found to be related to an increase in involuntary memories (i.e., the spontaneous recall of personal memories), and to lower self-concept clarity and insight. Positive and negative dimensions of psychosis correlated differently with autobiographical recollection characteristics, measured at both trait (Studies 1 and 2) and state levels (Study 2). Positive-like symptoms (in particular hallucination-proneness) showed a stronger and more consistent pattern of correlations than negative-like symptoms. These findings call for a dimensional approach to the relationship between autobiographical memory and psychosis symptoms in clinical and non-clinical individuals, to better understand the breakdown of autobiographical memory in the psychopathology of psychosis.

A comparative study of theory of mind in taxon-like clusters of psychometric schizotypes and individuals at genetic risk for schizophrenia

Introduction: Clinical and family studies suggest that alterations of theory of mind (ToM) represent a marker of genetic liability to schizophrenia. Findings regarding ToM in schizotypy are less consistent. The study aimed to explore whether this might be due to an insufficient account of the heterogeneity of schizotypy in prior research and/or the fact that in psychometric schizotypy ToM alterations could manifest as subtle peculiarities rather than overt errors of mentalising.Methods: Individuals without a family history of psychosis (n = 150) were assigned to low, positive, negative, and high mixed schizotypy classes based on a cluster analysis of 1322 subjects who completed the Schizotypal Personality Questionnaire. The classes were compared on their performance of faux pas tasks with 77 adult first-degree relatives of schizophrenia patients, who represent individuals at genetic risk for schizophrenia. Besides overt errors, subtle alterations in ToM were analysed using expert judgment.Results: The relatives tended to make overt errors and demonstrated specific features of intentional reasoning. None of the schizotypal classes showed similar trends.Conclusions: The results complement the literature on the subjective-objective disjunction in psychometric schizotypes and did not provide evidence that ToM anomalies are a marker of genetic liability to schizophrenia in this cohort.

Relationship between the domains of theory of mind, social dysfunction, and oxytocin in schizophrenia

Social dysfunction, manifested by impaired social cognition, is contributing to poorer prognosis of patients with schizophrenia. Growing evidence indicates that oxytocin acts as a neurotransmitter in the regulation of social cognition. It still lacks a thorough understanding of how oxytocin is linked with deficits in social cognition and social functioning in schizophrenia. To this end, we aimed to study the role of plasma oxytocin levels in the relationship between subdomains of social cognition and social dysfunction in patients with schizophrenia. Social Functioning Scale was administered to measure social dysfunction while Faux Pas Recognition Test was used to assess the Theory of Mind (ToM) in 40 patients with schizophrenia and 40 age-matched healthy controls. Patients with schizophrenia exhibited more deficits in ToM, more severe social dysfunction, and had lower plasma oxytocin levels, relative to healthy controls. A pooled correlation analysis of all participants revealed significant effects of plasma oxytocin levels on the ToM and social dysfunction. In patients with schizophrenia, plasma oxytocin levels were positively correlated with the affective but not cognitive component of the ToM, and the effects of plasma oxytocin levels on social functioning were partially mediated by affective ToM. Our findings underscore the importance of oxytocin as a potential predictor of ToM and social functioning in patients with schizophrenia. It may be worthwhile for future studies of oxytocin in schizophrenia to focus on an affected behavioral domain, e.g., social cognition, rather than diagnosis, and the targeted domain should be deconstructed into more detailed subdomains.

The relationship between negative symptoms, social cognition, and social functioning in patients with first episode psychosis

INTRODUCTION

Social functioning is severely affected in psychotic disorders. Negative symptoms and social cognition seem to play an important role in social functioning, although the preponderance and relationship between these three domains is not clear. In this study, we sought to assess the interrelation between social cognition, social functioning, and the expressiveness and experiential factors of negative symptoms in first-episode psychosis (FEP).

SAMPLE AND METHODS

216 patients, participants in a multicentre study (AGES-CM), comprised our study sample. The WHO Disability Assessment Schedule (WHODAS 2.0) was used to assess functioning, whereas the Positive and Negative Schizophrenia Syndrome Scale (PANSS) was used to measure the severity of negative symptoms, and the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) was applied to assess the emotional processing component of social cognition. Network analyses were conducted with the aim of analysing the patterns of relationships between social cognition, social functioning, and the expressiveness and experiential factors of negative symptoms.

RESULTS

Our findings suggest that there is a direct relationship between social cognition and social functioning (weight = -.077), but also an indirect connection between them, mediated by the experiential (but not the expressiveness) factor of negative symptoms (weight = 0.300).

DISCUSSION

The importance of the affectation of subdomains of social cognition, as well as the role of negative symptoms, specifically the experiential factor, in the functioning of patients with FEP seems to be relevant. The inclusion of these factors in prevention and treatment programs would thus allow us to reduce their impact on the social functioning of these patients.

Episodic Memory and Schizophrenia: From Characterization of Relational Memory Impairments to Neuroimaging Biomarkers

Episodic memory research in schizophrenia has a long history already which has clearly established significant impairments and strong associations with brain measures and functional outcome. The purpose of this chapter is not to make an exhaustive review of the recent literature but to highlight some relatively recent developments in the cognitive neuroscience field of episodic memory and schizophrenia. Hence, we present a contemporary view focusing specifically of relational memory which represents a form of episodic memory that refers to associations or binding among items or elements presented together. We describe the major tasks used and illustrate how their combination with brain imaging has: (1) favored the use of experimental memory tasks to isolate specific processes with specific neural correlates, (2) led to a distributed view of the neural correlates of memory impairments in schizophrenia where multiple regions are contributing, and (3) made possible the identification of fMRI biomarkers specific to episodic memory. We then briefly propose what we see as the next steps for memory research in schizophrenia so that the impact of this work can be maximized.

Understanding others as a mediator between verbal memory and negative symptoms in schizophrenia-spectrum disorder

From the onset of schizophrenia, verbal memory (VM) deficits and negative symptoms are strongly associated, and both additively predict functional outcomes. Emotion recognition (ER) and theory of mind (ToM; the ability to infer others' mental states), two components of social cognition, are also particularly affected in schizophrenia. Explanatory models of negative symptoms have integrated these cognitive impairments as potential precursors and previous studies revealed relationships between ER and/or ToM and VM, as well as with negative symptoms, but the organization of these associations remains unclear. We aimed to determine whether impairments in VM and social cognition sequentially pave the way for negative symptoms in schizophrenia. To this end, we used mediation analyses. One hundred and forty participants with a diagnosis of schizophrenia or schizoaffective disorder were recruited. First, correlational analyses were conducted between our variables of interest. The mediating effect of social cognition between VM and negative symptoms was then examined using the PROCESS macro. Variables of interest were significantly correlated (r = |0.166| to |0.391|), except for ER and negative symptoms. Only the serial multiple mediation model with 2 mediators (ER followed by ToM) revealed a significant indirect effect of VM on negative symptoms (β = - 0.160, 95% CI = -.370 to -.004). This relationship was selective for expressive negative symptoms (e.g., blunted affect and alogia). This study illustrates the richness of the relationship between cognitive deficits and negative symptoms and provides additional information for the involvement of social cognition in negative symptoms' etiology.

Neurocognitive functions in persistent negative symptoms following a first episode of psychosis

Negative symptoms are present at the onset of psychosis and their persistence is significantly associated with poor psychosocial functioning and lower quality of life. Persistent negative symptoms (PNS) may be idiopathic or secondary to other factors such as depression, positive symptoms, and medication side-effects. Several studies have examined neurocognitive functions in early psychosis patients with PNS relative to non-PNS, but have not systematically controlled for secondary PNS (sPNS). The latter may have a distinct neurocognitive profile that could obscure differences between PNS and non-PNS. Using a large (n = 425) sample, we examined neurocognitive functions in PNS, sPNS, and non-PNS and hypothesized that PNS would be associated with greater impairments relative to non-PNS. Following admission to an early intervention program, a neurocognitive battery was administered after at least 3 months of treatment, and symptom data collected during a subsequent 6-month period were used to classify patients as PNS, sPNS and non-PNS. At month 12, both PNS and sPNS groups had significantly lower level of functioning relative to the non-PNS group but the sPNS group experienced higher levels of depressive and positive symptoms and were on a higher dose of antipsychotics. Relative to non-PNS, PNS patients exhibited significant impairments in verbal memory and working memory, whereas sPNS patients exhibited a trend towards greater impairments in verbal memory. This study confirms that the presence of PNS or sPNS negatively influences functioning with more selective cognitive impairments found in PNS, providing evidence that these groups of patients could benefit from different personalised interventions.

Sex differences in association between clinical correlates and cognitive impairment in patients with chronic schizophrenia

Schizophrenia is a heterogeneous disorder with sex differences in clinical manifestations and cognitive function. However, the nature of its sex-specific relationship between clinical manifestations and cognitive impairment remains equivocal. This study aimed to explore the sex differences in the association between cognitive function and clinical features of hospitalized patients with schizophrenia. A total of 251 schizophrenia patients (males/females = 167/84) and 178 healthy controls (males/females = 84/94) were enrolled. Cognitive function was assessed through the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB). The Positive and Negative Syndrome Scale (PANSS) was used to evaluate psychiatric symptoms in patients. Both male and female patients performed more impaired than their counterparts on all MCCB tests. However, only the scores of category fluency, attention and reasoning/problem solving of female patients were significantly lower than those of male patients. Multivariate regression analyses demonstrated that attention was independently associated with negative symptoms in female patients, and general psychopathology in male patients. Negative symptoms were also independently associated with verbal learning and memory and social cognition only in male patients, while general psychopathology was independently associated with symbol coding only in female patients. Our results suggest that there are noticeable sex differences in clinical features, cognitive impairment and their associations in schizophrenia patients. These sex-specific associations may provide useful information for future studies aimed at predicting and interfering with the outcome of schizophrenia from a sex perspective.

Factorial Structure of the Serbian Version of the Clinical Assessment Interview for Negative Symptoms - Evidence for Three Factors of Negative Symptoms

Introduction: Negative symptoms are a common occurrence in patients with psychosis spectrum disorders. Previous analysis of the latent structure of the Clinical Assessment Interview for Negative Symptoms (CAINS) - which was developed to advance the assessment of negative symptomatology - showed two underlying sub-domains (Motivation and Pleasure; Expression). Recent findings indicate that a more complex structure might be more applicable. Aim: To evaluate the psychometric properties of the Serbian version of the CAINS in a sample of outpatients (N = 67) with psychosis spectrum disorders. Materials and Methods: Negative symptoms and general level of psychopathology were assessed with Serbian translations of the CAINS, the 53-item version of the Brief Symptom Inventory (BSI), and the 24-item version of the Brief Psychiatric Rating Scale (BPRS). Principal component analysis (PCA) was carried out on the CAINS items, and correlation analyses were done to assess its convergent and discriminant validity. Results: Our results showed an excellent internal consistency (Cronbach's alpha = 0.92). PCA revealed a three-component solution consisting of Expressiveness and Motivation for Social and Family Relationships (Factor 1), Motivation for Vocational Activities (Factor 2), and Motivation for Recreation (Factor 3). Convergent validity was supported by significant correlations with the Negative symptoms domain of the BPRS (Factor 1, 0.695, p < 0.01; Factor 2, 0.352, p < 0.05; Factor 3, 0.452, p < 0.01). When assessing discriminant validity, weak correlations were found with BPRS and BSI scores. Conclusion: The Serbian version of CAINS is a valid, reliable and useful tool for the assessment of negative symptomatology. Our findings support a three-factor structure of CAINS, which indicates that the construct is more complex than envisaged by the original conceptualization of two distinct factors.