Understanding of Faux Pas in patients with schizophrenia

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.

Evidence of the role of the cerebellum in cognitive theory of mind using voxel-based lesion mapping

Theory of Mind (ToM) is a social-cognitive skill that allows the understanding of the intentions, beliefs, and desires of others. There is a distinction between affective and cognitive ToM, with evidence showing that these processes rely on partially distinct neural networks. The role of the cerebellum in social cognition has only been rarely explored. In this study, we tested whether the cerebellum is necessary for cognitive and affective ToM performance. We investigated adults with traumatic brain injury (n = 193) and healthy controls (n = 52) using voxel-based lesion-symptom mapping (VLSM) and by measuring the impact on functional connectivity. First, we observed that damage to the cerebellum affected pure Cognitive ToM processing. Further, we found a lateralization effect for the role of the cerebellum in cognitive ToM with participants with left cerebellar injury performing worse than those with right cerebellar injury. Both VLSM and standard statistical analysis provided evidence that left cerebellar Crus I and lobule VI contributed to ToM processing. Lastly, we found that disconnection of the left thalamic projection and the left fronto-striatal fasciculus was associated with poor cognitive ToM performance. Our study is the first to reveal direct causal neuropsychological evidence for a role of the cerebellum in some but not all types of ToM, processing. It reinforces the idea that social cognition relies on a complex network functionally connected through white matter pathways that include the cerebellum. It supports evidence that the neural networks underpinning the different types of ToM can be differentiated.

Negative symptoms in schizophrenia, assessed by the brief negative symptom scale, self-evaluation of negative symptom scale, and social cognition: a gender effect

OBJECTIVE

Negative symptoms of schizophrenia can be related to social cognition. The aim was to measure a relationship between the results on the new scales for the assessment of negative symptoms such as the Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the measures of social cognition.

METHODS

The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period. They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for social cognition such as the Facial Emotion Identification Test, Reading the Mind in Eyes Test, Strange Stories and Faux Pas Test.

RESULTS

Male patients obtained higher scores than females when assessed by the BNSS. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and both parts of the Faux Pas test and obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in males.

CONCLUSIONS

Gender differences were found in the assessment of negative symptoms by a clinical scale and the relationship between negative symptoms and social cognition.KEY POINTSFemale patients scored better in the BNSS, PSP and both parts of the Faux-Pas testGender differences were present in the assessment of negative symptoms by clinical (BNSS) but not the self-assessment (SNS) scale.Female patients obtained a significant correlation between the results of the SNS scale, BNSS, PSP, and the affective part of the Faux-Pas test what was not the case in male subjects.