Social cognition in the course of psychosis and its correlation with biomarkers in a male cohort

Anticholinergic load: A commonly neglected and preventable risk to cognition during schizophrenia treatment?

Background

Cognitive impairment is a widespread feature of schizophrenia, affecting nearly 80 % of patients. Prior research has linked the anticholinergic burden of psychiatric medications to these cognitive deficits. However, the impact of the anticholinergic burden from medications for physical morbidity remains underexplored. This study aimed to evaluate the anticholinergic burden of psychiatric and physical medications in patients with schizophrenia and assess its impact on cognitive function.

Methods

A total of 178 patients with schizophrenia were recruited. The assessments included an ad hoc questionnaire for collecting demographic and clinical data. Anticholinergic burden was evaluated using the cumulative Drug Burden Index (cDBI) for each participant, and cognitive function was assessed using MATRICS. Psychopathology was measured using the PANSS, CDSS, CAINS, and the CGI-S. Statistical analysis included Student's t-tests, ANOVA, Pearson correlations, and multiple linear regressions.

Results

The average cDBI was 1.3 (SD = 0.9). The model developed explained 40.80 % of the variance. The variable with the greatest weight was the cDBI (B = -11.148, p = 0.010). Negative-expression (B = -2.740, p = 0.011) and negative-experiential (B = -1.175, p = 0.030) symptoms were also associated with lower global cognitive score. However, more years of education (B = 5.140, p < 0.001) and cigarettes per day (B = 1.331, p < 0.001) predicted a better global cognitive score.

Conclusion

This study identified specific predictors of global cognition in schizophrenia, with anticholinergic burden emerging as the strongest factor. Our findings underscore the importance of considering the anticholinergic burden of treatments, in addition to negative symptoms, when designing interventions to optimize or maintain cognitive function in patients with schizophrenia.

Mentalizing impairments and hypermentalizing bias in individuals with first-episode schizophrenia-spectrum disorder and at-risk mental state: the differential roles of neurocognition and social anxiety

Mentalizing, or theory of mind (ToM), impairments and self-referential hypermentalizing bias are well-evident in schizophrenia. However, findings compared to individuals with at-risk mental states (ARMS) are inconsistent, and investigations into the relationship between social cognitive impairments and social anxiety in the two populations are scarce. This study aimed to examine and compare these deficits in first-episode schizophrenia-spectrum disorder (FES) and ARMS, and to explore potential specific associations with neurocognition and symptomatology. Forty patients with FES, 40 individuals with ARMS, and 40 healthy controls (HC) completed clinical assessments, a battery of neurocognitive tasks, and three social cognitive tasks. The comic strip and hinting tasks were used to measure non-verbal and verbal mentalizing abilities, and the gaze perception task was employed to assess self-referential hypermentalizing bias. FES and ARMS showed comparable mentalizing impairments and self-referential hypermentalizing bias compared to HC. However, only ambiguous self-referential gaze perception (SRGP) bias remained significantly different between three groups after controlling for covariates. Findings suggested that self-referential hypermentalizing bias could be a specific deficit and may be considered a potential behavioral indicator in early-stage and prodromal psychosis. Moreover, working memory and social anxiety were related to the social cognitive impairments in ARMS, whereas higher-order executive functions and positive symptoms were associated with the impairments in FES. The current study indicates the presence of stage-specific mechanisms of mentalizing impairments and self-referential hypermentalizing bias, providing insights into the importance of personalized interventions to improve specific neurocognitive domains, social cognition, and clinical outcomes for FES and ARMS.

Cortisol and cytokines in schizophrenia: A scoping review

Background

With a complex etiology and chronic, disabling evolution, schizophrenia continues to represent a challenge for patients, clinicians, and researchers alike. Recent emphasis in research on finding practical blood-based biomarkers for diagnosis improvement, disease development prediction, and therapeutic response monitoring in schizophrenia, led to studies aiming at elucidating a connection between stress and inflammation markers.

Methods

We set here to explore recent literature aiming to understand the connection between cytokines and cortisol level changes in individuals with schizophrenia and their potential relevance as markers of clinical improvement under treatment. A search was completed in Pubmed, Embase, Web of Science, and APAPsycInfo databases with search terms: (cytokines) AND (cortisol) AND (schizophrenia). This provided 43 results from Pubmed, 82 results from Embase, 52 results from Web of Science, and 9 results from APA PsycInfo. After removing articles not fitting the criteria, 13 articles were selected.

Results

While all studies included assess cortisol levels in individuals with schizophrenia, most of them included a healthy control group for comparisons there is diversity in the inflammation markers assessed - the most frequent being the IL-2, IL-4, IL-6, IL-8, and TNF-α. Eleven of the 13 studies compare stress and inflammatory markers in individuals with schizophrenia to healthy controls, one study compares two subgroups of patients with schizophrenia, and one study compares pre- and post-measures in the same group of individuals with schizophrenia.

Conclusions

The focus of the studies within the topic is diverse. Many of the selected studies found correlations between cortisol and inflammation markers, however, the direction of correlation and inflammatory markers included differed. A variety of mechanisms behind cortisol and immunological changes associated with schizophrenia were considered. Evidence was found in these studies to suggest that biological immune and stress markers may be associated with clinical improvement in participants with schizophrenia, however, the exact mechanisms remain to be determined.

Social interaction, psychotic disorders and inflammation: A triangle of interest

Social interaction difficulties are a hallmark of psychotic disorders, which in some cases can be definitely traced back to autoimmunological causes. Interestingly, systemic and intrathecal inflammation have been shown to significantly influence social processing by increasing sensitivity to threatening social stimuli, which bears some resemblance to psychosis. In this article, we review evidence for the involvement of systemic and intrathecal inflammatory processes in psychotic disorders and how this might help to explain some of the social impairments associated with this group of disorders. Vice versa, we also discuss evidence for the immunomodulatory function of social interactions and their potential role for therapeutic interventions in psychotic disorders.

Meta-analysis of peripheral insulin-like growth factor 1 levels in schizophrenia

OBJECTIVE

We aimed to investigate if there is a significant difference in peripheral insulin-like growth factor 1 (IGF-1) levels between schizophrenia patients and healthy controls and to determine whether a difference exists before and after initiation of antipsychotics.

METHODS

PubMed/MEDLINE, Scopus, and Web of Science were searched up to March 27, 2022. Original clinical studies of any type that reported peripheral blood, serum or plasma IGF-1 levels measured after fasting in schizophrenia patients and/or healthy control group were selected based on inclusion and exclusion criteria. Data were analyzed using Meta-Essentials: Workbooks for meta-analysis and pooled through random-effects meta-analyses.

RESULTS

Twelve publications met eligibility criteria. Schizophrenia patients under antipsychotic treatment had significantly lower peripheral IGF-1 levels compared to healthy controls (n = 632, Hedges' g -0.42, 95% CI from -0.79 to -0.04, p = .006, I²  = 70.38%), while no significant difference was found between schizophrenia patients regardless of the antipsychotic treatment status and healthy controls, as well as between antipsychotic naïve or free schizophrenia patients and healthy controls, and before and after initiation of antipsychotic treatment. However, high heterogeneity was observed and its potential sources in some of the subgroup analyses included sample type and region.

CONCLUSIONS

Schizophrenia patients under antipsychotic treatment seem to have lower peripheral IGF-1 levels compared to healthy controls. Additional studies with larger and more homogenous samples are needed to confirm these findings.

Rethinking Immunity and Cognition in Clinical High Risk for Psychosis

It is well known that schizophrenia is associated with cognitive impairment, reduced cortical grey matter and increased circulating concentrations of inflammatory cytokines. However, the relationship between these findings is not clear. We outline the influential neuroinflammatory hypotheses that raised cytokines provoke a damaging immune response in microglia that results in reduced grey matter and associated cognitive performance. We investigated whether such an interaction might be detectable in the prodromal period as illness emerges from the Clinical High Risk for Psychosis (CHR-P). Meta-analyses suggest that compared with controls, impaired cognition and reduced grey matter are already present by the prodrome and that greater decrements are present in those who later develop symptoms. In contrast, the few cytokine studies report no abnormalities in CHR-P except that interleukin-6 (IL-6) levels were raised versus controls and to a greater extent in the future patients, in one study. We noted that cognitive impairment and less cortical grey matter are more severe in schizophrenia than in affective disorders, but that increased cytokine levels are similarly prevalent across disorders. We found no studies correlating cytokine levels with cognitive impairment in CHR-P but such correlations seem unlikely given the minimal relationship reported in a recent meta-analysis of the many cytokine-cognition studies in established illness. From this and other evidence, we conclude that neuroinflammation is not a core feature of schizophrenia nor a substrate for reduced grey matter volume or cognitive function. We draw attention instead to the emerging evidence that brain-resident immune cells and signalling molecules such as Tregs and IL-6, which are influenced by schizophrenia risk genes, regulate and are necessary for the development and function of neuron-glia interaction. We suggest that cognitive impairment in schizophrenia can be seen as a convergence of genetic and immune-neurodevelopmental dysregulation whereas raised cytokines are a consequence of impaired Tregs control of systemic inflammation.

Relapse of first-episode schizophrenia patients and neurocognitive impairment: The role of dopaminergic and anticholinergic burden

BACKGROUND

The prevention of relapse may be a key factor to diminish the cognitive impairment of first-episode schizophrenia (FES) patients. We aimed to ascertain the effects of relapse, and dopaminergic and anticholinergic treatment burdens on cognitive functioning in the follow-up.

METHODS

Ninety-nine FES patients participated in this study. Cognitive assessments were performed at baseline and after 3 years of follow-up or, in those patients who relapsed, after &gt;2 months of stabilization of the new acute psychotic episode. The primary outcomes were final cognitive dimensions.

RESULTS

Repeated measures MANOVA analyses showed improvements in the whole sample on the end-point assessments in processing speed and social cognition. However, only impairment in social cognition showed a significant interaction with relapse by time in this sample. Relapse in FES patients was significantly associated with poor performance on end-point assessments of working memory, social cognition and global cognitive score. Anticholinergic burden, but not dopaminergic burden, was associated with verbal memory impairment. These significant associations resulted after controlling for baseline cognitive functioning, relapse and dopaminergic burden.

CONCLUSIONS

The relationship between relapse and cognitive impairment in recovered FES patients seems to be particularly complex at the short-term follow-up of these patients. While relapse was associated with working memory, social cognition impairments and global cognitive score, anticholinergic burden might play an additional worsening effect on verbal memory. Thus, tailoring or changing antipsychotics and other drugs to reduce their anticholinergic burden may be a potential modifiable factor to diminish cognitive impairment at this stage of the illness.

The impact of inflammation on neurocognition and risk for psychosis: a critical review

Neurocognitive difficulties are highly prevalent among people with schizophrenia and have been linked to increased inflammation, as well as dysfunction and disability. Poor neurocognitive functioning has also been documented in individuals at clinical high risk for psychosis (CHR) and a burgeoning literature point to alterations in inflammation markers in this population. However, there is limited information regarding the putative link between inflammation and neurocognition in CHR individuals, and the potential role of inflammation in the development of cognitive difficulties and psychosis. As previous reports indicate that early treatment in schizophrenia is associated with better outcomes, there is an urgent need to identify neurobiological mechanisms underlying cognitive deterioration and psychosis in CHR individuals to provide them with care prior to significant cognitive and functional declines. To address this gap in the literature, we review and summarize the relevant literatures on inflammation and neurocognitive dysfunction in schizophrenia and CHR individuals, point to remaining gaps, and suggest directions for future research.