Interplay among positive and negative symptoms, neurocognition, social cognition, and functioning in clinically stable patients with schizophrenia: a network analysis

Centrality statistics of symptom networks of schizophrenia: a systematic review

The network theory of psychological disorders posits that systems of symptoms cause, or are associated with, the expression of other symptoms. Substantial literature on symptom networks has been published to date, although no systematic review has been conducted exclusively on symptom networks of schizophrenia, schizoaffective disorder, and schizophreniform (people diagnosed with schizophrenia; PDS). This study aims to compare statistics of the symptom network publications on PDS in the last 21 years and identify congruences and discrepancies in the literature. More specifically, we will focus on centrality statistics. Thirty-two studies met the inclusion criteria. The results suggest that cognition, and social, and occupational functioning are central to the network of symptoms. Positive symptoms, particularly delusions were central among participants in many studies that did not include cognitive assessment. Nodes representing cognition were most central in those studies that did. Nodes representing negative symptoms were not as central as items measuring positive symptoms. Some studies that included measures of mood and affect found items or subscales measuring depression were central nodes in the networks. Cognition, and social, and occupational functioning appear to be core symptoms of schizophrenia as they are more central in the networks, compared to variables assessing positive symptoms. This seems consistent despite heterogeneity in the design of the studies.

A Systematic Review and Meta-Analysis of the Association Between Psychopathology and Social Functioning in Schizophrenia

BACKGROUND

Impaired social functioning is a major, but under-elucidated area of schizophrenia. It's typically understood as consequential to, eg, negative symptoms, but meta-analyses on the subject have not examined psychopathology in a broader perspective and there's severe heterogeneity in outcome measures. To enhance functional recovery from schizophrenia, a more comprehensive understanding of the nature of social functioning in schizophrenia is needed.

STUDY DESIGN

In this systematic review and meta-analysis, we searched PubMed, PsycInfo, and Ovid Embase for studies providing an association between psychopathology and social functioning. Meta-analyses of the regression and correlation coefficients were performed to explore associations between social functioning and psychopathology, as well as associations between their subdomains.

STUDY RESULTS

Thirty-six studies with a total of 4742 patients were included. Overall social functioning was associated with overall psychopathology (95% CI [-0.63; -0.37]), positive symptoms (95% CI [-0.39; -0.25]), negative symptoms (95% CI [-0.61; -0.42]), disorganized symptoms (95% CI [-0.54; -0.14]), depressive symptoms (95% CI [-0.33; -0.11]), and general psychopathology (95% CI [-0.60; -0.43]). There was significant heterogeneity in the results, with I2 ranging from 52% to 92%.

CONCLUSIONS

This is the first systematic review and meta-analysis to comprehensively examine associations between psychopathology and social functioning. The finding that all psychopathological subdomains seem to correlate with social functioning challenges the view that impaired social functioning in schizophrenia is mainly a result of negative symptoms. In line with classical psychopathological literature on schizophrenia, it may be more appropriate to consider impaired social functioning as a manifestation of the disorder itself.

Assessment of interrelationships between cognitive performance, symptomatic manifestation and social functioning in the acute and clinical stability phase of schizophrenia: insights from a network analysis

BACKGROUND

It has been shown that various aspects of clinical manifestation of schizophrenia are strongly related to social functioning. However, it remains unknown as to whether similar factors predict social functioning at various stages of psychosis. Therefore, the present study aimed to compare the effects of interconnections between various domains of psychopathology and neurocognition on social functioning in people during acute phase of psychosis and those during remission of positive and disorganization symptoms using a network analysis.

METHODS

Two independent samples of individuals with schizophrenia spectrum disorders were enrolled (89 inpatients during acute phase and 90 outpatients during remission of positive and disorganization symptoms). Clinical assessment covered the levels of functioning, positive, negative and depressive symptoms. Cognition was recorded using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Data were analyzed by means of the network analysis. Two separate networks of clinical symptoms, social functioning, and cognition (i.e., in patients during acute phase of psychosis and remitted outpatients with schizophrenia) were analyzed and compared with respect to the measures of centrality (betweenness, closeness, strength, and expected influence) and edge weights.

RESULTS

In both networks, the majority of centrality metrics (expected influence, strength, and closeness) had the highest values for the RBANS scores of attention (the sum of scores from two tasks, i.e., digit span and coding) and immediate memory. In both networks, social functioning was directly connected to positive, negative and depressive symptoms as well as the RBANS scores of attention and language. Additionally, in remitted patients, social functioning was directly connected to the RBANS score of immediate memory.

CONCLUSIONS

Findings from the present study indicate the central role of cognitive deficits, especially those related to attention, processing speed, working and immediate memory in shaping functional impairments regardless of schizophrenia phase. Therapeutic interventions that aim to improve functional capacity need to target these domains of neurocognitive performance.

Deficits in Key Brain Network for Social Interaction in Individuals with Schizophrenia

Individuals with schizophrenia (SZ) show impairment in social functioning. The reward network and the emotional salience network are considered to play important roles in social interaction. The current study investigated alterations in the resting-state (rs-) amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo) and functional connectivity (fc) in the reward network and the emotional salience network in SZ patients. MRI scans were collected from 60 subjects, including 30 SZ patients and 30 matched healthy controls. SZ symptoms were measured using the Positive and Negative Syndrome Scale (PANSS). We analyzed the ALFF, fALFF and ReHo in key brain regions in the reward network and emotional salience network as well as rs-fc among the bilateral amygdala, lateral orbitofrontal cortex (OFC), medial OFC and insula between groups. The SZ patients demonstrated increased ALFF in the right caudate and right putamen, increased fALFF and ReHo in the bilateral caudate, putamen and pallidum, along with decreased fALFF in the bilateral insula. Additionally, reduced rs-fc was found between the right lateral OFC and the left amygdala, which simultaneously belong to the reward network and the emotional salience network. These findings highlight the association between impaired social functioning in SZ patients and aberrant resting-state ALFF, fALFF, ReHo and fc. Future studies are needed to conduct network-based statistical analysis and task-state fMRI, reflecting live social interaction to advance our understanding of the mechanism of social interaction deficits in SZ.

The motivation and pleasure deficits but not expressivity affects social functioning through cognitive function in male patients with schizophrenia: A structural equation model

OBJECTIVE

This study aims to compare cognitive function and social functioning in male schizophrenia patients with deficit syndrome (DS) and non-DS, and to explore the associations among two different dimensions of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits), cognitive function and social functioning base on a Structural Equation Model (SEM).

METHODS

The current study enrolled 161 male schizophrenia patients and 120 age- and education- matched healthy controls. The DS and non-DS group were categorized by the Chinese version of Schedule for the Deficit Syndrome (SDS). The psychotic and negative symptoms were evaluated by the Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS). The Social functioning was measured by Scale of Social function in Psychosis Inpatients (SSPI). A battery of classical neurocognitive tests was used for assessing cognition including sustained vigilance/attention, cognitive flexibility, ideation fluency and visuospatial memory.

RESULTS

Our study indicated that DS patients performed worser in cognitive function and social functioning than non-DS patients. The SEM model demonstrated that MAP significantly affected social functioning through direct influence and mediation of cognitive function. However, our results found that EXP had little influence on cognitive function and social function.

CONCLUSION

Our findings provided evidence supporting that DS may represent as a subtype of schizophrenia, and the MAP factor play a pivotal role to influence the cognitive and social functioning in schizophrenia patients.

The Role of Two Factors of Negative Symptoms and Cognition on Social Functioning in Male Patients with Schizophrenia: A Mediator Model

OBJECTIVE

This study aims to compare the cognitive function and social functioning in male patients with deficit syndrome (DS) and non-DS, and to explore whether cognitive function serves as a mediator in the relationship between the two factors of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits, and social functioning in schizophrenia patients.

METHODS

One hundred and fifty-six male patients with schizophrenia and 109 age- and education-matched normal controls were enrolled in the current study. The Chinese version of a Schedule for Deficit Syndrome (SDS) was used for DS and non-DS categorization. The Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS) were used to assess psychotic and negative symptoms in patients. The Social-Adaptive Functioning Evaluation (SAFE) was adopted to evaluate patients' social functioning, and a battery of classical neurocognitive tests was used to assess cognition, including sustained vigilance/attention, cognitive flexibility, ideation fluency, and visuospatial memory.

RESULTS

We found that male patients with DS performed worse in all four cognitive domains and social functioning compared to non-DS patients. Both total negative symptoms and its two factors were significantly associated with all four domains of cognition and social functioning in male patients. Interestingly, our results indicate that only cognitive flexibility mediates the relationship between negative symptoms and social functioning in schizophrenia patients, but there were no differences between EXP and MAP negative factors in this model.

CONCLUSION

Our findings suggest that DS patients may represent a unique clinical subgroup of schizophrenia, and the integrated interventions targeting both negative symptoms and cognition, especially cognitive flexibility, may optimally improve functional outcomes in schizophrenia patients.