Cortisol and Inflammatory Biomarkers Predict Poor Treatment Response in First Episode Psychosis

Coping styles do not interact with the association between childhood trauma history and the immune-inflammatory phenotype of schizophrenia: Findings from a cross-sectional study

Adverse childhood experiences (ACEs) are a well-known risk factor of schizophrenia. Moreover, individuals with schizophrenia are likely to use maladaptive stress coping strategies. Although it has been reported that a history of ACEs might be associated with a pro-inflammatory phenotype in patients with schizophrenia, the interacting effect of coping styles on this association has not been tested so far. In the present study, we aimed to investigate the levels of immune-inflammatory markers in patients with schizophrenia and healthy controls (HCs), taking into consideration a history of ACEs and coping strategies. Participants included 119 patients with schizophrenia and 120 HCs. Serum levels of 26 immune-inflammatory markers were determined. A history of any categories of ACEs was significantly more frequent in patients with schizophrenia. Moreover, patients with schizophrenia were significantly more likely to use emotion-focused coping and less likely to use active coping strategies compared to HCs. The levels of interleukin(IL)-6, RANTES, and tumor necrosis factor-α (TNF-α), appeared to be elevated in patients with schizophrenia after adjustment for potential confounding factors in all tested models. Participants reporting a history of any ACEs had significantly higher levels of TNF-α and IL-6. No significant main and interactive effects of active strategies as the predominant coping on immune-inflammatory markers with altered levels in patients with schizophrenia were found. Findings from the present study indicate that ACEs are associated with elevated TNF-α and IL-6 levels regardless of schizophrenia diagnosis and predominant coping styles.

Nutrition and schizophrenia: associations worthy of continued revaluation

BACKGROUND

Accumulating evidence have shown that diet and nutrition play significant roles in mental illness, such as depression, anxiety and bipolar disorder. However, comprehensive evaluation of the relationship between nutrition and schizophrenia is lacking.

OBJECTIVE

The present review aims to synthetic elaborate the associations between nutrition and schizophrenia. Relevant studies on dietary patterns, macronutrients, micronutrients were performed through a literature search to synthesize the extracted data.

SUMMARY

Dietary interventions may help prevent the occurrence of schizophrenia, or delay symptoms: Healthy diets like nutritious plant-based foods and high-quality protein, have been linked to reducing the risk or symptoms of schizophrenia. Moreover, diet high in saturated fat and sugar is linked to more serious outcomes of schizophrenia. Additionally, when N-acetylcysteine acts as an adjuvant therapy, the overall symptoms of schizophrenia are significantly reduced. Also nascent evidence showed mental disorders may be related to intestinal microbiota dysfunction. Our study offered important insights into the dietary habits of patients with schizophrenia and the potential impact of nutritional factors on the disease. We also emphasized the need for further research, particularly in the form of large randomized double-blind controlled trials, to better understand the effects of nutrients on schizophrenia symptoms in different populations and disease types.

[Management of treatment resistance-Treatment-resistant schizophrenia]

Despite a very high prevalence and substantial impairments among affected individuals, treatment-resistant schizophrenia (TRS) has not been sufficiently researched in clinical research in the field of psychiatric disorders and the pathophysiology is still poorly understood. A better clinical and pathophysiological understanding of this heterogeneous and severely affected population of people with persistent symptoms in different domains is necessary in order not only to be able to intervene early but also to develop novel therapeutic strategies or individualized treatment approaches. This review article presents the state of the art criteria of the pharmacological TRS, neurobiological disease models and predictive factors for TRS as well as the phenomenon of pseudo-treatment resistance and the clinical management of TRS. In the future, not only the use of operationalized criteria and definitions of TRS in longitudinal studies and randomized-controlled trials (RCTs) are paramount, but also the observation of trajectories with the integration of multimodal longitudinal phenotyping and the longitudinal collection of clinical routine data in academic research, which will be possible in the newly created German Center for Mental Health (DZPG).

Cortisol in functional neurological disorders: State, trait and prognostic biomarkers

OBJECTIVE

Biological stress dysregulation, such as a flattened cortisol awakening response (CAR), has been identified in functional neurological disorder (FND). This longitudinal study aimed to explore whether CAR alterations in FND serve as state or trait biomarkers, assessing temporal changes in cortisol and clinical outcomes to test its prognostic value.

METHODS

Salivary cortisol was measured in 53 patients with mixed FND at two visits separated by eight months (M0 and M8). CAR was calculated based on five consecutive samples, each taken with 15-min time intervals, collected upon awakening, whereas cortisol amplitude (CAmp) was calculated as the difference between the morning peak and the afternoon trough. Clinical outcome was assessed with the Functional Movement Disorder Rating Scale (S-FMDRS), Clinical global impression (CGI) scores for severity (CGI-S) and improvement (CGI-I) and the short-form health survey (SF-36).

RESULTS

No differences in CAR levels were found between M0 and M8 regardless of clinical outcome (remained flattened). However, a good clinical outcome was associated with an earlier peak in the CAR (p = .013, odds ratio: 1.78; 95%-confidence interval: 0.095-1.13). A higher CAmp at M0 predicted a better outcome at M8 (β = 1.14, 95%-confidence interval:0.15-2.13, p = .03).

CONCLUSION

A flattened CAR might represent a trait marker for FND, when an earlier peak in the CAR may serve as a state biomarker. The CAmp demonstrates predictive power for clinical outcome, potentially representing a prognostic biomarker for FND. Further replication and follow-up studies are essential to confirm this suggested role of cortisol as a multifaceted biomarker of FND.

Association between psychiatric admissions in patients with schizophrenia and IL-6 plasma levels polygenic score

Schizophrenia diagnosis and admission history were associated with a polygenic score (PGS) for schizophrenia based on a subset of variants that act by modifying the expression of genes whose expression is also modified by antipsychotics. This gene set was enriched in cytokine production. Interleukin-6 (IL-6) is the only cytokine whose plasma levels were associated both with schizophrenia diagnosis and with acute decompensations in the largest meta-analysis. Therefore, we hypothesized that an IL-6 PGS, but not other cytokines PGSs, would be associated with schizophrenia chronicity/psychiatric admissions. Using the IL-6 PGS model from The PGS Catalog, IL-6 PGS was calculated in 427 patients with schizophrenia and data regarding admission history. Association between IL-6 PGS and chronicity, measured as number and duration of psychiatric admissions, or ever readmission was analyzed by multivariate ordinal and logistic regression, respectively. Specificity of results was assessed by analysis of PGSs from the other cytokines at The PGS Catalog with meta-analytic evidence of association with schizophrenia diagnosis or acute decompensations, IL-1RA, IL-4, IL-8, and IL-12. IL-6 PGS was associated with schizophrenia chronicity, explaining 1.51% of variability (OR = 1.29, 95% CI 1.07-1.55, P = 0.007). There was no association with ever readmission. Other cytokines PGSs were not associated with chronicity. Association with IL-6 PGS was independent of association with schizophrenia PGS. Our results provide evidence that genetically regulated higher levels of IL-6 are involved in schizophrenia chronicity, highlighting the relevance of immunity processes for a subgroup of patients.

Microglia-neuron interactions in schizophrenia

Multiple lines of evidence implicate increased neuroinflammation mediated by glial cells to play a key role in neurodevelopmental disorders such as schizophrenia. Microglia, which are the primary innate immune cells of the brain, are crucial for the refinement of the synaptic circuitry during early brain development by synaptic pruning and the regulation of synaptic plasticity during adulthood. Schizophrenia risk factors as genetics or environmental influences may further be linked to increased activation of microglia, an increase of pro-inflammatory cytokine levels and activation of the inflammasome resulting in an overall elevated neuroinflammatory state in patients. Synaptic loss, one of the central pathological hallmarks of schizophrenia, is believed to be due to excess removal of synapses by activated microglia, primarily affecting glutamatergic neurons. Therefore, it is crucial to investigate microglia-neuron interactions, which has been done by multiple studies focusing on post-mortem brain tissues, brain imaging, animal models and patient iPSC-derived 2D culture systems. In this review, we summarize the major findings in patients and in vivo and in vitro models in the context of neuron-microglia interactions in schizophrenia and secondly discuss the potential of anti-inflammatory treatments for the alleviation of positive, negative, and cognitive symptoms.

Relationship between blood-based inflammatory indices and clinical score of schizophrenia patients: A cross-sectional study

Schizophrenia is a severe mental disorder that may involve inflammation. Inflammatory indices, such as the neutrophil to lymphocyte ratio (NLR), the monocyte to lymphocyte ratio (MLR), the platelet to lymphocyte ratio (PLR), and the systemic inflammation index (SII), are simple and inexpensive measures of inflammation that have been associated with various diseases. However, few studies have compared these indices and their relationships with clinical symptoms in schizophrenia. We conducted a cross-sectional study of 121 schizophrenia patients (101 males, 20 females). We measured the blood-based inflammatory indices (NLR, MLR, PLR, and SII) and assessed the clinical symptoms of schizophrenia using the Positive and Negative Syndrome Scale (PANSS). Statistical analyses were performed to examine the correlations and effects of the inflammatory indices on PANSS scores. We found that NLR, MLR, PLR, and SII were positively correlated with PANSS total score, PANSS positive score, PANSS negative score, and general psychopathology score (adjusted P < 0.02 for all correlations). Subgroup analysis showed that correlations between inflammatory indices and the clinical scores differed by gender. In males, all inflammatory indices were positively correlated with all clinical scores. On the other hand, in females, only NLR and SII were positively correlated with all clinical scores. After adjusting for confounders, we also found that NLR was a predictor of PANSS total score (β = 23, adjusted P < 0.02), PANSS positive score (β = 2.6, adjusted P = 0.03), PANSS negative score (β = 6.8, adjusted P < 0.02), and PANSS general psychopathology score (β = 13.6, adjusted P < 0.02), while SII was only a predictor for PANSS total score (β = -0.00003, adjusted P = 0.01) and general psychopathology scores (β = -0.00002, adjusted P < 0.02). These findings suggest that inflammation is involved in the pathophysiology and clinical manifestations of schizophrenia, and that blood-based inflammatory indices may serve as screening tools or indicators for the inflammatory status and severity of symptoms of schizophrenia patients.

Greater Choline-Containing Compounds and Myo-inositol in Treatment-Resistant Versus Responsive Schizophrenia: A 1H-Magnetic Resonance Spectroscopy Meta-analysis

BACKGROUND

The neurobiology of treatment-resistant schizophrenia (TRS) is poorly understood, and meta-analytic consensus regarding magnetic resonance spectroscopic profiles of glutamate, choline-containing compounds, myo-inositol, and other metabolites in the condition is lacking.

METHODS

In this meta-analysis, we examined published findings for N-acetylaspartate, choline-containing compounds (phosphocholine+glycerophosphocholine), myo-inositol, creatine+phosphocreatine, glutamate, and glutamate+glutamine in the anterior cingulate cortex and dorsal striatum in people with TRS versus non-TRS as well as TRS versus healthy control participants (HCs) and TRS versus ultra TRS (i.e., TRS with clozapine resistance). A MEDLINE search revealed 9 articles including 239 people with pooled TRS and ultra TRS, 59 with ultra TRS, 175 with non-TRS, and 153 (HCs) that met meta-analytic criteria.

RESULTS

Significant effects included higher anterior cingulate cortex phosphocholine+glycerophosphocholine and myo-inositol in the pooled TRS and ultra TRS group than in both the non-TRS group and HCs as well as higher dorsal striatal phosphocholine+glycerophosphocholine in ultra TRS versus HCs, but no differences in other regional metabolites.

CONCLUSIONS

The observed metabolite profile in TRS (higher phosphocholine+glycerophosphocholine and myo-inositol signal) is consistent with the hypothesis that TRS has a neuroinflammatory component, although this meta-analysis is not a critical test of that hypothesis. A similar profile is seen in healthy aging, which is known to involve increased neuroinflammation and glial activation. Because the overall number of datasets was low, however, results should be considered preliminary and highlight the need for additional studies of brain metabolites in TRS and their possible association with inflammatory processes.

The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

The Role of Total White Blood Cell Count in Antipsychotic Treatment for Patients with Schizophrenia

BACKGROUND

Total white blood cell count (TWBCc), an index of chronic and low-grade inflammation, is associated with clinical symptoms and metabolic alterations in patients with schizophrenia. The effect of antipsychotics on TWBCc, predictive values of TWBCc for drug response, and role of metabolic alterations require further study.

METHODS

Patients with schizophrenia were randomized to monotherapy with risperidone, olanzapine, quetiapine, aripiprazole, ziprasidone, perphenazine or haloperidol in a 6-week pharmacological trial. We repeatedly measured clinical symptoms, TWBCc, and metabolic measures (body mass index, blood pressure, waist circumference, fasting blood lipids and glucose). We used mixed-effect linear regression models to test whether TWBCc can predict drug response. Mediation analysis to investigate metabolic alteration effects on drug response.

RESULTS

At baseline, TWBCc was higher among patients previously medicated. After treatment with risperidone, olanzapine, quetiapine, perphenazine, and haloperidol, TWBCc decreased significantly (p < 0.05). Lower baseline TWBCc predicted greater reductions in Positive and Negative Syndrome Scale (PANSS) total and negative scores over time (p < 0.05). We found significant mediation of TWBCc for effects of waist circumference, fasting low-density lipoprotein cholesterol, and glucose on reductions in PANSS total scores and PANSS negative subscale scores (p < 0.05).

CONCLUSION

TWBCc is affected by certain antipsychotics among patients with schizophrenia, with decreases observed following short-term, but increases following long-term treatment. TWBCc is predictive of drug response, with lower TWBCc predicting better responses to antipsychotics. It also mediates the effects of certain metabolic measures on improvement of negative symptoms. This indicates that the metabolic state may affect clinical manifestations through inflammation.

The association between clinical, sociodemographic, familial, and environmental factors and treatment resistance in schizophrenia: A machine-learning-based approach

BACKGROUND

Prediction of treatment resistance in schizophrenia (TRS) would be helpful to reduce the duration of ineffective treatment and avoid delays in clozapine initiation. We applied machine learning to identify clinical, sociodemographic, familial, and environmental variables that are associated with TRS and could potentially predict TRS in the future.

STUDY DESIGN

Baseline and follow-up data on trait(-like) variables from the Genetic Risk and Outcome of Psychosis (GROUP) study were used. For the main analysis, we selected patients with non-affective psychotic disorders who met TRS (n = 200) or antipsychotic-responsive criteria (n = 423) throughout the study. For a sensitivity analysis, we only selected patients who met TRS (n = 76) or antipsychotic-responsive criteria (n = 123) at follow-up but not at baseline. Random forest models were trained to predict TRS in both datasets. SHapley Additive exPlanation values were used to examine the variables' contributions to the prediction.

STUDY RESULTS

Premorbid functioning, age at onset, and educational degree were most consistently associated with TRS across both analyses. Marital status, current household, intelligence quotient, number of moves, and family loading score for substance abuse also consistently contributed to the prediction of TRS in the main or sensitivity analysis. The diagnostic performance of our models was modest (area under the curve: 0.66-0.69).

CONCLUSIONS

We demonstrate that various clinical, sociodemographic, familial, and environmental variables are associated with TRS. Our models only showed modest performance in predicting TRS. Prospective large multi-centre studies are needed to validate our findings and investigate whether the model's performance can be improved by adding data from different modalities.

Is there any association between cognitive deficits and immune markers in Acute and Transient psychotic disorders? A pilot study

BACKGROUND

There are studies to support association between immune function and cognition in patients with schizophrenia (SZ). However, there are no such study which had tried to explore the same in patients with Acute and transient psychotic disorders (ATPDs), which is considered to similar in presentation to SZ.

METHODS

This is an extended analysis of the study published in which we had recruited 19 subjects with ATPDs in acute phase of illness were age-/gender-matched with patients schizophrenia in remission. Clinical assessment and immune-marker levels (IL-6,IL-8,IL-17) were carried out along with follow -up repeat immune-marker levels assessment in the ATPD group was conducted after remission status was ensured (at least 3 months after resolution of acute phase). Cognitive assessment was done on Montreal Cognitive Assessment Scale (MoCA) in both the groups (ATPD in both phases and in SZ).

RESULTS

The mean MoCA total score was 12.05 (SD-5.0) in the acute phase and 27.05 (SD-2.46) in the remission phase in the ATPD group which was statistically significant. When compared with patients with SZ in remission, patients with ATPD in remission performed better in all domains of MoCA, however only statistically significant differences in the total MoCA score and in the visuospatial domain scores of MoCA. No significant association between any of the immune marker levels (IL-6, Il-8 and IL-17) with any domains of the MoCA in patients with ATPD neither in the acute phase nor in the remission phase was found. Additionally, no significant association between the cognitive scores in the MoCA domains of the patients with schizophrenia and immune marker levels was found too.

CONCLUSION

To conclude, the present study's findings suggested that there existed definite cognitive deficits in patients with ATPDs in both acute and remission phase and in patients with SZ. However, the study could not establish any relationship/association between cognitive deficits/scores in patients with ATPDs in both phases as well as in patients with SZ with immune marker levels.

The association between inflammation and kynurenine pathway metabolites in electroconvulsive therapy for schizophrenia: Implications for clinical efficacy

The kynurenine pathway (KP) of tryptophan has been implicated in the pathogenesis of schizophrenia and its interaction with the immune system has been suggested to play a role. In this study, 28 schizophrenia patients and 25 healthy controls were recruited and divided into different inflammatory subgroups using a two-step recursive clustering analysis. Cytokine gene expression and plasma KP metabolites were measured before, during and after treatment. Our findings indicated that schizophrenia patients had lower levels of Tryptophan (TRP), N-formylkynurenine (NFK), xanthinic acid (XA), quinolinic acid (QA), kynurenic acid (KYNA), KYNA/KYN and QA/KYNA, but higher levels of IL-18 mRNA, KYN/TRP compared to healthy controls (all p < 0.05). After electroconvulsive therapy (ECT), patients with low inflammation achieved better clinical improvement (PANSS scores) compared to those with high inflammation (F = 5.672, P = 0.025), especially in negative symptoms (F = 6.382, P = 0.018, η2 = 0.197). While IL-18 mRNA (F = 32.910, P < 0.0001) was significantly decreased following ECT, the KYN/TRP (F = 3.455, p = 0.047) and KYNA/TRP (F = 4.264, P = 0.026) only significantly decreased in patients with low inflammation. Correlation analyses revealed that baseline IL-18 gene expression significantly correlated with pre- (r = 0.537, p = 0.008) and post-KYNA/TRP (r = 0.443, p = 0.034), post-KYN/TRP (r = 0.510, p = 0.013), and post-negative symptoms (r = 0.525, p = 0.010). Moreover, baseline TRP (r = -0.438, p = 0.037) and XA (r = -0.516, p = 0.012) were negatively correlated with baseline PANSS, while post-KYN (r = -0.475, p = 0.022), 2-AA (r = -0.447, p = 0.032) and KYN/TRP (r = -0.566, p = 0.005) were negatively correlated with Montreal Cognitive Assessment (MoCA) following ECT. Overall, these findings suggested that the association between inflammation and kynurenine pathway plays an essential role in mechanism of ECT for schizophrenia and that the regulation of ECT on KP is influenced by inflammatory characteristics, which may relate to clinical efficacy in schizophrenia.

Selected neuroendocrine factors as potential molecular biomarkers of early non-affective psychosis course in relation to treatment outcome: A pilot study

The aim of this pilot study was to find whether the dysregulation of neuroendocrine biomarker signaling pathways in the first episode of non-affective psychosis is a predictive factor of treatment outcome. Patients with the first episode of non-affective psychosis (N = 29) were examined at admission, at discharge, and at follow-up (N = 23). The biomarkers included serum aldosterone, cortisol, free thyroxine, thyroid stimulating hormone, and prolactin. We revealed lower baseline aldosterone and higher baseline cortisol concentrations in patients with very good outcome compared to those with good outcome after one year. We failed to reveal any significant association between treatment outcome and neurohumoral biomarkers in the whole sample at 1-year follow-up. However, baseline aldosterone concentrations negatively correlated with total PANSS scores at the discharge. Lower baseline aldosterone and higher baseline cortisol concentrations have the potential to predict a more favorable outcome for patients with the first episode of psychosis.

Immunological Biomarkers as Predictors of Treatment Response in Psychotic Disorders

Psychotic disorders, notably schizophrenia, impose a detrimental burden on both an individual and a societal level. The mechanisms leading to psychotic disorders are multifaceted, with genetics and environmental factors playing major roles. Increasing evidence additionally implicates neuro-inflammatory processes within at least a subgroup of patients with psychosis. While numerous studies have investigated anti-inflammatory add-on treatments to current antipsychotics, the exploration of immunological biomarkers as a predictor of treatment response remains limited. This review outlines the current evidence from trials exploring the potential of baseline inflammatory biomarkers as predictors of the treatment effect of anti-inflammatory drugs as add-ons to antipsychotics and of antipsychotics alone. Several of the studies have found correlations between baseline immunological biomarkers and treatment response; however, only a few studies incorporated baseline biomarkers as a primary endpoint, and the findings thus need to be interpreted with caution. Our review emphasizes the need for additional research on the potential of repurposing anti-inflammatory drugs while utilizing baseline inflammatory biomarkers as a predictor of treatment response and to identify subgroups of individuals with psychotic disorders where add-on treatment with immunomodulating agents would be warranted. Future studies investigating the correlation between baseline inflammatory markers and treatment responses can pave the way for personalized medicine approaches in psychiatry centred around biomarkers such as specific baseline inflammatory biomarkers in psychotic disorders.

Interaction between high interleukin-2 and high cortisol levels is associated with psychopathology in patients with chronic schizophrenia

BACKGROUND

Both cortisol and interleukins appear at abnormal levels in schizophrenia. Our previous study has shown that cortisol and interleukins are associated with psychopathology and response to antipsychotic medications in a relatively small sample size of patients with schizophrenia. The current study was designed to investigate how cortisol, interleukins (ILs) and their interactions would correlate with clinical presentation in a relatively large sample size of patients with schizophrenia.

METHODS

We compared serum cortisol, IL-2, IL-6, and IL-8 levels in 162 medicated schizophrenia patients (including 27 patients in remission) and 62 healthy controls. Serum levels of cortisol and interleukins were measured by radioimmunoassay and quantitative ELISA, respectively. Clinical symptoms were assessed according to the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Patients with schizophrenia had significantly higher levels of cortisol and IL-2 compared to controls. Patients in remission had higher levels of IL-6 than non-remitting patients. PANSS positive symptoms, general psychopathology, cortisol and IL-2 were the most central nodes in the cortisol-IL-symptom network. The interaction between cortisol and IL-2 was associated with PANSS positive symptoms, general psychopathology and depressive factor. For patients with cortisol level above the median, IL-2 was negatively associated with PANSS positive symptoms and general psychopathology.

CONCLUSIONS

Our results indicated that the interaction between cytokines and cortisol may be associated with the pathophysiology of some symptoms in chronic schizophrenia. In particular, the interaction between cortisol and IL-2 is associated with the clinical phenotypes of schizophrenia.

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.

Altered neutrophil-to-lymphocyte ratio in patients with non-affective first episode psychosis and its relationship with symptom severity and cognitive impairment

Signatures of immune dysregulation as clinical biomarker for psychosis have remained unclear. We aimed to compare the Neutrophil-to-lymphocyte ratio (NLR) of patients with acute non-affective first-episode psychosis (FEP) with healthy controls after accounting for emotional states. We also explored the associations of NLR with symptom severity, onset profile and cognitive functions. The NLR was enumerated from complete blood count taken within a week of assessment. All FEP patients were rated on the Positive and Negative Syndrome Scale (PANSS) and the Clinician Global Impression-Severity (CGI-S) with verbal memory and executive functions assessed with the Cambridge Neuropsychological Test Automated Battery. Prevailing emotional state was measured with Beck Depression Inventory-II and Beck Anxiety Inventory. Out of seventy-nine consecutive FEP patients presenting to the study site, twenty-seven subjects were eligible and recruited. Twenty-seven age-/sex-matched controls were recruited. FEP patients had an NLR of 1.886 over the controls after accounting for scores on emotional states. The NLR of FEP patients was positively associated with CGI-S scores, PANSS positive symptom, disorganization and excitation scores. There was no significant correlation between NLR with the duration of untreated psychosis and cognitive performances. These findings support using NLR as a clinical biomarker in FEP, purporting further prospective study to measure NLR changes in the course of treatment.

The association between peripheral inflammation, brain glutamate and antipsychotic response in Schizophrenia: Data from the STRATA collaboration

Glutamate and increased inflammation have been separately implicated in the pathophysiology of schizophrenia and the extent of clinical response to antipsychotic treatment. Despite the mechanistic links between pro-inflammatory and glutamatergic pathways, the relationships between peripheral inflammatory markers and brain glutamate in schizophrenia have not yet been investigated. In this study, we tested the hypothesis that peripheral levels of pro-inflammatory cytokines would be positively associated with brain glutamate levels in schizophrenia. Secondary analyses determined whether this relationship differed according to antipsychotic treatment response. The sample consisted of 79 patients with schizophrenia, of whom 40 were rated as antipsychotic responders and 39 as antipsychotic non-responders. Brain glutamate levels were assessed in the anterior cingulate cortex (ACC) and caudate using proton magnetic resonance spectroscopy (1H-MRS) and blood samples were collected for cytokine assay on the same study visit (IL-6, IL-8, IL-10, TNF- α and IFN-γ). Across the whole patient sample, there was a positive relationship between interferon-gamma (IFN-γ) and caudate glutamate levels (r = 0.31, p = 0.02). In the antipsychotic non-responsive group only, there was a positive relationship between interleukin-8 (IL-8) and caudate glutamate (r = 0.46, p = 0.01). These findings provide evidence to link specific peripheral inflammatory markers and caudate glutamate in schizophrenia and may suggest that this relationship is most marked in patients who show a poor response to antipsychotic treatment.

Inflammatory disequilibrium and lateral ventricular enlargement in treatment-resistant schizophrenia

Treatment-resistant schizophrenia (TRS) patient respond poorly to antipsychotics. Inflammatory imbalance involving pro- and anti-inflammatory cytokines may play an important role in the mechanism of antipsychotic-medication response. This study aimed to investigate immune imbalance and how the latter relates to clinical manifestations in patients with TRS. The level of net inflammation was estimated by evaluating the immune-inflammatory response system and compensatory immune-regulatory reflex system (IRS/CIRS) in 52 patients with TRS, 47 with non-TRS, and 56 sex and age matched healthy controls. The immune biomarkers mainly included macrophagic M1, T helper, Th-1, Th-2, Th-17, and T regulatory cytokines and receptors. Plasma cytokine levels were measured using enzyme-linked immunosorbent assay. Psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). Subcortical volumes were quantified using a 3-T Prisma Magnetic Resonance Imaging scanner. The results showed that (1) patients with TRS were characterized by activated pro-inflammatory cytokines and relatively insufficient anti-inflammatory cytokines, with an elevated IRS/CIRS ratio indicating a new homeostatic immune setpoint; (2) IRS/CIRS ratio was positively correlated with larger lateral ventricle volume and higher PANSS score in patients with TRS. Our findings highlighted the inflammatory disequilibrium as a potential pathophysiological process of TRS.

Immunological protein profiling of first-episode psychosis patients identifies CSF and blood biomarkers correlating with disease severity

BACKGROUND AND HYPOTHESIS

Immune activation is suggested to play an important role in psychosis. In this study, a large number of immune-related proteins were analyzed to obtain a more comprehensive picture of immune aberrations in schizophrenia.

STUDY DESIGN

Ninety-two immune markers were analyzed by the Olink Protein Extension Assay (Inflammatory Panel) in plasma and cerebrospinal fluid (CSF) from 77 first-episode psychosis (FEP) patients (of which 43 later received the diagnosis of schizophrenia) and 56 healthy controls, all recruited from the Karolinska Schizophrenia Project (KaSP), Stockholm, Sweden.

STUDY RESULTS

Differential analysis showed that 12 of 92 inflammatory proteins were significantly higher in the plasma of FEP patients (n = 77) than in controls, and several proteins were positively correlated with disease severity. Patients from the same cohort diagnosed with schizophrenia (n = 43), showed significantly higher levels of 15 plasma proteins compared to controls whereas those not receiving this diagnosis showed no significant differences. The presently used OLINK inflammatory panel allowed the detection of only 47 CSF proteins of which only CD5 differed between patients and controls.

CONCLUSIONS

The levels of several peripheral immune markers, particularly those interfering with WNT/β-catenin signaling, were significantly higher in patients with FEP than in healthy controls and associated with illness severity.

Alterations in inflammatory markers after a 12-week exercise program in individuals with schizophrenia-a randomized controlled trial

Background

In individuals with schizophrenia, inflammation is associated with depression, somatic comorbidity and reduced quality of life. Physical exercise is known to reduce inflammation in other populations, but we have only limited knowledge in the field of schizophrenia. We assessed inflammatory markers in plasma samples from individuals with schizophrenia participating in an exercise intervention randomized controlled trial. We hypothesized that (i) physical exercise would reduce levels of inflammatory markers and (ii) elevated inflammatory status at baseline would be associated with improvement in cardiorespiratory fitness (CRF) following intervention.

Method

Eighty-two individuals with schizophrenia were randomized to a 12-week intervention of either high-intensity interval training (HIIT, n = 43) or active video gaming (AVG, n = 39). Participants were assessed at baseline, post intervention and four months later. The associations between exercise and the inflammatory markers soluble urokinase plasminogen activator receptor, c-reactive protein, tumor necrosis factor (TNF), soluble TNF receptor 1 and interleukin 6 (IL-6) were estimated using linear mixed effect models for repeated measures. For estimating associations between baseline inflammation and change in CRF, we used linear regression models.

Results

Our main findings were (i) TNF and IL-6 increased during the intervention period for both groups. Other inflammatory markers did not change during the exercise intervention period; (ii) baseline inflammatory status did not influence change in CRF during intervention, except for a positive association between baseline IL-6 levels and improvements of CRF to post intervention for both groups.

Conclusion

In our study, HIIT and AVG for 12-weeks had no reducing effect on inflammatory markers. Patients with high baseline IL-6 levels had a positive change in CRF during intervention. In order to increase our knowledge regarding association between inflammatory markers and exercise in individuals with schizophrenia, larger studies with more frequent and longer exercise bout duration are warranted.

Serum immune markers and transition to psychosis in individuals at clinical high risk

Individuals at clinical high risk (CHR) for psychosis have been found to have altered cytokine levels, but whether these changes are related to clinical outcomes remains unclear. We addressed this issue by measuring serum levels of 20 immune markers in 325 participants (n = 269 CHR, n = 56 healthy controls) using multiplex immunoassays, and then followed up the CHR sample to determine their clinical outcomes. Among 269 CHR individuals, 50 (18.6 %) developed psychosis by two years. Univariate and machine learning techniques were used to compare levels of inflammatory markers in CHR subjects and healthy controls, and in CHR subjects who had (CHR-t), or had not (CHR-nt) transitioned to psychosis. An ANCOVA identified significant group differences (CHR-t, CHR-nt and controls) and post-hoc tests indicated that VEGF levels and the IL-10/IL-6 ratio were significantly higher in CHR-t than CHR-nt, after adjusting for multiple comparisons. Using a penalised logistic regression classifier, CHR participants were distinguished from controls with an area-under the curve (AUC) of 0.82, with IL-6 and IL-4 levels the most important discriminating features. Transition to psychosis was predicted with an AUC of 0.57, with higher VEGF level and IL-10/IL-6 ratio the most important discriminating features. These data suggest that alterations in the levels of peripheral immune markers are associated with the subsequent onset of psychosis. The association with increased VEGF levels could reflect altered blood-brain-barrier (BBB) permeability, while the link with an elevated IL-10/IL-6 ratio points to an imbalance between anti- and pro-inflammatory cytokines.

Schizophrenia and obesity: May the gut microbiota serve as a link for the pathogenesis?

Schizophrenia (SZ) places a tremendous burden on public health as one of the leading causes of disability and death. SZ patients are more prone to developing obesity than the general population from the clinical practice. The development of obesity frequently causes poor psychiatric outcomes in SZ patients. In turn, maternal obesity during pregnancy has been associated with an increased risk of SZ in offspring, suggesting that these two disorders may have shared neuropathological mechanisms. The gut microbiota is well known to serve as a major regulator of bidirectional interactions between the central nervous system and the gastrointestinal tract. It also plays a critical role in maintaining physical and mental health in humans. Recent studies have shown that the dysbiosis of gut microbiota is intimately associated with the onset of SZ and obesity through shared pathophysiological mechanisms, particularly the stimulation of immune inflammation. Therefore, gut microbiota may serve as a common biological basis for the etiology in both SZ and obesity, and the perturbed gut-brain axis may therefore account for the high prevalence of obesity in patients with SZ. On the basis of these findings, this review provides updated perspectives and intervention approaches on the etiology, prevention, and management of obesity in SZ patients by summarizing the recent findings on the role of gut microbiota in the pathogenesis of SZ and obesity, highlighting the role of gut-derived inflammation.

V. Hegelstad W, Joa I, Opjordsmoen SE, Rund BR, Røssberg JI, Simonsen E, Johannessen JO, Larsen TK, Haahr UH, McGlashan TH, Friis S, Melle I. Childhood trauma, antipsychotic medication, and symptom remission in first-episode psychosis

BACKGROUND

To what extent psychotic symptoms in first-episode psychosis (FEP) with a history of childhood interpersonal trauma (CIT) are less responsive to antipsychotic medication is not known. In this longitudinal study, we compare symptom trajectories and remission over the first 2 years of treatment in FEP with and without CIT and examine if differences are linked to the use of antipsychotics.

METHODS

FEP (N = 191) were recruited from in- and outpatient services 1997-2000, and assessed at baseline, 3 months, 1 and 2 years. Inclusion criteria were 15-65 years, actively psychotic with a DSM-IV diagnosis of psychotic disorder and no previous adequate treatment for psychosis. Antipsychotic medication is reported as defined daily dosage (DDD). CIT (<18) was assessed with the Brief Betrayal Trauma Survey, and symptomatic remission based on scores from the Positive and Negative Syndrome Scale.

RESULTS

CIT (n = 63, 33%) was not associated with symptomatic remission at 2 years follow-up (71% in remission, 14% in relapse), or time to first remission (CIT 12/ no-CIT 9 weeks, p = 0.51). Those with CIT had significantly more severe positive, depressive, and excited symptoms. FEP with physical (N = 39, 20%) or emotional abuse (N = 22, 14, 7%) had higher DDD at 1 year (p < 0.05). Mean DDD did not excerpt a significant between-group effect on symptom trajectories of positive symptoms.

CONCLUSION

Results indicate that antipsychotic medication is equally beneficial in the achievement of symptomatic remission in FEP after 2 years independent of CIT. Still, FEP patients with CIT had more severe positive, depressive, and excited symptoms throughout.

Protocol for the Psychosis Immune Mechanism Stratified Medicine (PIMS) trial: a randomised double-blind placebo-controlled trial of single-dose tocilizumab in patients with psychosis

INTRODUCTION

Evidence suggests a potentially causal role of interleukin 6 (IL-6), a pleiotropic cytokine that generally promotes inflammation, in the pathogenesis of psychosis. However, no interventional studies in patients with psychosis, stratified using inflammatory markers, have been conducted to assess the therapeutic potential of targeting IL-6 in psychosis and to elucidate potential mechanism of effect. Tocilizumab is a humanised monoclonal antibody targeting the IL-6 receptor to inhibit IL-6 signalling, licensed in the UK for treatment of rheumatoid arthritis. The primary objective of this study is to test whether IL-6 contributes to the pathogenesis of first episode psychosis and to examine potential mechanisms by which IL-6 affects psychotic symptoms. A secondary objective is to examine characteristics of inflammation-associated psychosis.

METHODS AND ANALYSIS

A proof-of-concept study employing a randomised, parallel-group, double-blind, placebo-controlled design testing the effect of IL-6 inhibition on anhedonia in patients with psychosis. Approximately 60 participants with a diagnosis of schizophrenia and related psychotic disorders (ICD-10 codes F20, F22, F25, F28, F29) with evidence of low-grade inflammation (IL-6≥0.7 pg/mL) will receive either one intravenous infusion of tocilizumab (4.0 mg/kg; max 800 mg) or normal saline. Psychiatric measures and blood samples will be collected at baseline, 7, 14 and 28 days post infusion. Cognitive and neuroimaging data will be collected at baseline and 14 days post infusion. In addition, approximately 30 patients with psychosis without evidence of inflammation (IL-6<0.7 pg/mL) and 30 matched healthy controls will be recruited to complete identical baseline assessments to allow for comparison of the characteristic features of inflammation-associated psychosis.

ETHICS AND DISSEMINATION

The study is sponsored by the University of Bristol and has been approved by the Cambridge East Research Ethics Committee (reference: 22/EE/0010; IRAS project ID: 301682). Study findings will be published in peer-review journals. Findings will also be disseminated by scientific presentation and other means.

TRIAL REGISTRATION NUMBER

ISRCTN23256704.

Risperidone response in patients with schizophrenia drives DNA methylation changes in immune and neuronal systems

Background: The choice of efficient antipsychotic therapy for schizophrenia relies on a time-consuming trial-and-error approach, whereas the social and economic burdens of the disease call for faster alternatives. Material & methods: In a search for predictive biomarkers of antipsychotic response, blood methylomes of 28 patients were analyzed before and 4 weeks into risperidone therapy. Results: Several CpGs exhibiting response-specific temporal dynamics were identified in otherwise temporally stable methylomes and noticeable global response-related differences were observed between good and bad responders. These were associated with genes involved in immunity, neurotransmission and neuronal development. Polymorphisms in many of these genes were previously linked with schizophrenia etiology and antipsychotic response. Conclusion: Antipsychotic response seems to be shaped by both stable and medication-induced methylation differences.

Inflammation and cognition in severe mental illness: patterns of covariation and subgroups

A potential relationship between dysregulation of immune/inflammatory pathways and cognitive impairment has been suggested in severe mental illnesses (SMI), such as schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, multivariate relationships between peripheral inflammatory/immune-related markers and cognitive domains are unclear, and many studies do not account for inter-individual variance in both cognitive functioning and inflammatory/immune status. This study aimed to investigate covariance patterns between inflammatory/immune-related markers and cognitive domains and further elucidate heterogeneity in a large SMI and healthy control (HC) cohort (SZ = 343, BD = 289, HC = 770). We applied canonical correlation analysis (CCA) to identify modes of maximum covariation between a comprehensive selection of cognitive domains and inflammatory/immune markers. We found that poor verbal learning and psychomotor processing speed was associated with higher levels of interleukin-18 system cytokines and beta defensin 2, reflecting enhanced activation of innate immunity, a pattern augmented in SMI compared to HC. Applying hierarchical clustering on covariance patterns identified by the CCA revealed a high cognition-low immune dysregulation subgroup with predominantly HC (24% SZ, 45% BD, 74% HC) and a low cognition-high immune dysregulation subgroup predominantly consisting of SMI patients (76% SZ, 55% BD, 26% HC). These subgroups differed in IQ, years of education, age, CRP, BMI (all groups), level of functioning, symptoms and defined daily dose (DDD) of antipsychotics (SMI cohort). Our findings suggest a link between cognitive impairment and innate immune dysregulation in a subset of individuals with severe mental illness.

Immune-mediated inflammatory markers in acute and transient psychotic disorders-comparison with schizophrenia: An exploratory comparative study

AIM

Considering Acute and Transient psychotic disorders (ATPDs) to be a close entity to Schizophrenia (SZ) with a completely different course and outcome, studies evaluating the immunological abnormalities are scarce in ATPDs. We analysed immune-mediated inflammatory marker levels [Interleukin-2 (IL-2), Interleukin-4 (IL-4), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-17 (IL-17) and Tumour necrosis factor-alpha (TNF-α)] in patients with ATPDs (in the acute phase and after remission), and compared these with patients with SZ in remission and with healthy controls.

METHODS

Ninteen subjects with ATPDs in acute phase of illness were age-/gender-matched with healthy controls and patients with schizophrenia in remission; recruited through purposive sampling. Clinical assessment and immune-marker levels were carried out in all the three groups. Follow -up repeat immune-marker levels assessment in the ATPD group was conducted after remission status was ensured. Immune-marker levels were compared across the three groups.

RESULTS

Patients with ATPDs had elevated levels of the pro-inflammatory cytokines IL-6 and IL-17 and low levels of IL-8 in the acute phase and low levels of IL-6 and elevated levels of IL-8 during the remission phase. Compared to patients with SZ in remission, patients with ATPD in remission had low levels of all the three pro-inflammatory cytokines (with significantly low IL-6 levels and non-significant, yet low levels of IL-8 and IL-17) and had significantly low and high levels of IL-6 and IL-8 respectively than healthy controls.

CONCLUSION

These findings suggest that there existed immunological abnormalities in the acute and remission phase of illness in patients with ATPDs compared to both patients with SZ in remission and healthy controls.

Depression trajectories and cytokines in schizophrenia spectrum disorders - A longitudinal observational study

Depression occurs frequently in all phases of schizophrenia spectrum disorders. Altered activity in the immune system is seen in both depression and schizophrenia. We aimed to uncover depressive trajectories in a sample of 144 adult individuals with schizophrenia spectrum disorders followed for one year, in order to identify possible cytokine profile differences. Patients were assessed longitudinally with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), where a score above 6 predicts depression. The serum cytokine concentrations for tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, IL-12p70 and IL-17A were measured using immunoassays. Latent growth curve models, multilevel models and latent class growth analysis (LCGA) were applied. The LCGA model supported three latent classes (trajectories) with differing CDSS profiles during the one-year follow-up: a high CDSS group (40.8 % of participants), a moderate CDSS group (43.9 %) and a low CDSS group (15.3 %). Five single PANSS items predicted affiliation to depressive trajectory: hallucinations, difficulty in abstract thinking, anxiety, guilt feelings and tension. In the high CDSS group, despite diminishing psychotic symptoms, depressive symptoms persisted throughout one year. The pro-inflammatory cytokines IFN-γ, IL-1β and TNF-α were differentially distributed between the depressive trajectories, although levels remained remarkably stable throughout 12 months. Significant changes were found for the anti-inflammatory cytokine IL-10 at baseline with an accompanying difference in change over time. More research is required to optimize future treatment stratification and investigate the contribution of inflammation in depressed patients with schizophrenia spectrum disorders.

Longitudinal study of inflammation and relapse in schizophrenia

INTRODUCTION

The clinical course of schizophrenia is often characterized by recurrent relapses. Blood inflammatory markers are altered in acute psychosis, and may be state markers for illness relapse in schizophrenia. Few studies have investigated longitudinal, intra-individual changes in inflammatory markers as a predictor of relapse. In the present study, we explored this association in a relapse prevention trial in patients with schizophrenia.

METHODS

We analyzed blood inflammatory markers in 200 subjects, with a mean 11 samples per subject, during the 30 month Preventing Relapse in schizophrenia: Oral Antipsychotics Compared to Injectable: eValuating Efficacy (PROACTIVE) trial. Associations between longitudinal changes in inflammatory markers and relapse were analyzed using a within-subjects design.

RESULTS

70 (35 %) of subjects relapsed during the study period. There were no significant differences in mean inflammatory marker levels based on relapse status (yes/no). Baseline levels of inflammatory markers did not predict incident relapse. Among subjects who relapsed, there was a significant decrease in mean blood IL-6 (n = 38, p = 0.019) and IFN-γ (n = 44, p = 0.012) levels from the visit before the relapse to the visit after relapse.

CONCLUSION

Although there was some evidence for inflammation as a potential state marker for acute psychosis, we did not find significant evidence for its utility as a relapse-predictive marker.

Serum complement proteins rather than inflammatory factors is effective in predicting psychosis in individuals at clinical high risk

Immunological/inflammatory factors are implicated in the development of psychosis. Complement is a key driver of inflammation; however, it remains unknown which factor is better at predicting the onset of psychosis. This study aimed to compare the alteration and predictive performance of inflammation and complement in individuals at clinical high risk (CHR). We enrolled 49 individuals at CHR and 26 healthy controls (HCs). Twenty-five patients at CHR had converted to psychosis (converter) by the 3-year follow-up. Inflammatory cytokines, including interleukin (IL)-1β, 6, 8, 10, tumor necrosis factor-alpha (TNF-alpha), macrophage colony-stimulating factor levels, and complement proteins (C1q, C2, C3, C3b, C4, C4b, C5, C5a, factor B, D, I, H) were measured by enzyme-linked immunosorbent assay at baseline. Except for TNF- alpha, none of the inflammatory cytokines reached a significant level in either the comparison of CHR individuals and HC or between CHR-converters and non-converters. The C5, C3, D, I, and H levels were significantly lower (C5, p = 0.006; C3, p = 0.009; D, p = 0.026; I, p = 0.016; H, p = 0.019) in the CHR group than in the HC group. Compared to non-converters, converters had significantly lower levels of C5 (p = 0.012) and C5a (p = 0.007). None of the inflammatory factors, but many complement factors, showed significant correlations with changes in general function and symptoms. None of the inflammatory markers, except for C5a and C5, were significant in the discrimination of conversion outcomes in CHR individuals. Our results suggest that altered complement levels in the CHR population are more associated with conversion to psychosis than inflammatory factors. Therefore, an activated complement system may precede the first-episode of psychosis and contribute to neurological pathogenesis at the CHR stage.

The Strategy of Targeting Peroxisome Proliferator-Activated Receptor (PPAR) in the Treatment of Neuropsychiatric Disorders

Peroxisome proliferator-activated receptors (PPARs) are nonsteroid nuclear receptors and transcription factors that regulate several neuroinflammatory and metabolic processes, recently involved in several neuropsychiatric conditions, including Alzheimer's disease, Parkinson's disease, major depressive disorder, post-traumatic stress disorder (PTSD), schizophrenia spectrum disorders, and autism spectrum disorders. PPARs are ligand-activated receptors that, following stimulation, induce neuroprotective effects by decreasing neuroinflammatory processes through inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) expression and consequent suppression of pro-inflammatory cytokine production. PPARs heterodimerize with the retinoid X-receptor (RXR) and bind to PPAR-responsive regulatory elements (PPRE) in the promoter region of target genes involved in lipid metabolism, synthesis of cholesterol, catabolism of amino acids, and inflammation. Interestingly, PPARs are considered functionally part of the extended endocannabinoid (eCB) system that includes the classic eCB, anandamide, which act at cannabinoid receptor types 1 (CB1) and 2 (CB2) and are implicated in the pathophysiology of stress-related neuropsychiatric disorders. In preclinical studies, PPAR stimulation improves anxiety and depression-like behaviors by enhancing neurosteroid biosynthesis. The peculiar functional role of PPARs by exerting anti-inflammatory and neuroprotective effects and their expression localization in neurons and glial cells of corticolimbic circuits make them particularly interesting as novel therapeutic targets for several neuropsychiatric disorders characterized by underlying neuroinflammatory/neurodegenerative mechanisms. Herein, we discuss the pathological hallmarks of neuropsychiatric conditions associated with neuroinflammation, as well as the pivotal role of PPARs with a special emphasis on the subtype alpha (PPAR-α) as a suitable molecular target for therapeutic interventions.

Early Life Stress, Neuroinflammation, and Psychiatric Illness of Adulthood

Stress exposure during early stages of life elevates the risk of developing psychopathologies and psychiatric illness in later life. The brain and immune system are not completely developed by birth and therefore continue develop after birth; this post birth development is influenced by several psychosocial factors; hence, early life stress (ELS) exposure can alter brain structural development and function. A growing number of experimental animal and observational human studies have investigated the link between ELS exposure and increased risk of psychopathology through alternations in the immune system, by evaluating inflammation biomarkers. Recent studies, including brain imaging, have also shed light on the mechanisms by which both the innate and adaptive immune systems interact with neural circuits and neurotransmitters, which affect psychopathology. Herein, we discuss the link between the experience of stress in early life and lifelong alterations in the immune system, which subsequently lead to the development of various psychiatric illnesses.

Interplay between activation of endogenous retroviruses and inflammation as common pathogenic mechanism in neurological and psychiatric disorders

Human endogenous retroviruses (ERVs) are ancestorial retroviral elements that were integrated into our genome through germline infections and insertions during evolution. They have repeatedly been implicated in the aetiology and pathophysiology of numerous human disorders, particularly in those that affect the central nervous system. In addition to the known association of ERVs with multiple sclerosis and amyotrophic lateral sclerosis, a growing number of studies links the induction and expression of these retroviral elements with the onset and severity of neurodevelopmental and psychiatric disorders. Although these disorders differ in terms of overall disease pathology and causalities, a certain degree of (subclinical) chronic inflammation can be identified in all of them. Based on these commonalities, we discuss the bidirectional relationship between ERV expression and inflammation and highlight that numerous entry points to this reciprocal sequence of events exist, including initial infections with ERV-activating pathogens, exposure to non-infectious inflammatory stimuli, and conditions in which epigenetic silencing of ERV elements is disrupted.

Dopamine, Immunity, and Disease

The neurotransmitter dopamine is a key factor in central nervous system (CNS) function, regulating many processes including reward, movement, and cognition. Dopamine also regulates critical functions in peripheral organs, such as blood pressure, renal activity, and intestinal motility. Beyond these functions, a growing body of evidence indicates that dopamine is an important immunoregulatory factor. Most types of immune cells express dopamine receptors and other dopaminergic proteins, and many immune cells take up, produce, store, and/or release dopamine, suggesting that dopaminergic immunomodulation is important for immune function. Targeting these pathways could be a promising avenue for the treatment of inflammation and disease, but despite increasing research in this area, data on the specific effects of dopamine on many immune cells and disease processes remain inconsistent and poorly understood. Therefore, this review integrates the current knowledge of the role of dopamine in immune cell function and inflammatory signaling across systems. We also discuss the current understanding of dopaminergic regulation of immune signaling in the CNS and peripheral tissues, highlighting the role of dopaminergic immunomodulation in diseases such as Parkinson's disease, several neuropsychiatric conditions, neurologic human immunodeficiency virus, inflammatory bowel disease, rheumatoid arthritis, and others. Careful consideration is given to the influence of experimental design on results, and we note a number of areas in need of further research. Overall, this review integrates our knowledge of dopaminergic immunology at the cellular, tissue, and disease level and prompts the development of therapeutics and strategies targeted toward ameliorating disease through dopaminergic regulation of immunity. SIGNIFICANCE STATEMENT: Canonically, dopamine is recognized as a neurotransmitter involved in the regulation of movement, cognition, and reward. However, dopamine also acts as an immune modulator in the central nervous system and periphery. This review comprehensively assesses the current knowledge of dopaminergic immunomodulation and the role of dopamine in disease pathogenesis at the cellular and tissue level. This will provide broad access to this information across fields, identify areas in need of further investigation, and drive the development of dopaminergic therapeutic strategies.

Increased blood neutrophil extracellular traps (NETs) associated with early life stress: translational findings in recent-onset schizophrenia and rodent model

Higher levels of interleukin (IL)-6 and elevated neutrophil counts are consistently reported in the blood of patients with schizophrenia. Stressors during childhood and/or adolescence are major socioenvironmental risk factors for schizophrenia and may contribute to immune dysregulation. Previous studies using blood cytokines to stratify patients with schizophrenia suggest that only a subset presents a low-grade inflammatory state. However, these studies have not addressed whether environmental factors such as childhood maltreatment contributed to identifying inflammatory clusters. Moreover, a neutrophil-related mechanism (Neutrophil Extracellular Traps; NETs) central to both the initiation and chronicity of autoimmune and inflammatory diseases has never been investigated in psychiatry. Elevated NETs in schizophrenia may predispose patients to inflammatory and autoimmune diseases resulting in reduced life expectancy. We, therefore, investigated NETs as a novel mechanism and biological target in early schizophrenia and their role together with IL-6 and childhood maltreatment in identifying cluster subgroups. We found increased NETs in the plasma of patients with early schizophrenia (n = 78) compared to both their unaffected siblings (n = 25) and community controls (n = 78), irrespective of sex, body mass index, psychoactive drug use, or tobacco smoking. Increased NETs in patients were unrelated to antipsychotic treatment, which was further tested in vitro using fresh neutrophils. By applying unsupervised two-step clustering analysis, we integrated values of NETs, IL-6, and childhood maltreatment scores. We identified two main clusters; childhood maltreatment scores and NETs were the most important variables contributing to cluster separation (high-CL1 and low-CL2), while IL-6 was the least contributor. Patients allocated in the high-CL1 (61.5%) had significantly higher childhood maltreatment scores, NETs, and IL-6 levels than the remaining groups (patients low-CL2, siblings, and controls high-CL1 and low-CL2). We complemented these findings with a rat model based on stress exposure during adolescence that results in several schizophrenia-like changes in adulthood. We found that adolescent stressed rats had higher NETs and IL-6 levels in serum compared to non-stressed rats with a tendency to produce more NETs from the bone marrow. Altogether, this study brings a novel cellular-based mechanism in schizophrenia that, combined with early-stress, could be useful to identify subgroups for more personalised treatments.

Gut microbiota alterations in stable outpatients with schizophrenia: findings from a case-control study

OBJECTIVE

The pathogenesis of schizophrenia is multidimensional and intensively studied. The gut-brain axis disturbances might play a significant role in the development of schizophrenia.

METHODS

We compared the gut microbiota of 53 individuals with schizophrenia and 58 healthy controls, using the 16S rRNA sequencing method. Individuals with schizophrenia were assessed using the following scales: the Positive and Negative Syndrome Scale, the Calgary Depression Scale for Schizophrenia, the Social and Occupational Functioning Assessment Scale and the Repeatable Battery for the Assessment of Neuropsychological Status.

RESULTS

No significant between-group differences in α-diversity measures were observed. Increased abundance of Lactobacillales (order level), Bacilli (class level) and Actinobacteriota (phylum level) were found in individuals with schizophrenia regardless of potential confounding factors, and using two independent analytical approaches (the distance-based redundancy analysis and the generalised linear model analysis). Additionally, significant correlations between various bacterial taxa (the Bacteroidia class, the Actinobacteriota phylum, the Bacteroidota phylum, the Coriobacteriales order and the Coriobacteria class) and clinical manifestation (the severity of negative symptoms, performance of language abilities, social and occupational functioning) were observed.

CONCLUSIONS

The present study indicates that gut microbiota alterations are present in European patients with schizophrenia. The abundance of certain bacterial taxa might be associated with the severity of negative symptoms, cognitive performance and general functioning. Nonetheless, additional studies are needed before the translation of our results into clinical practice.

Effects of add-on Celecoxib treatment on patients with schizophrenia spectrum disorders and inflammatory cytokine profile trial (TargetFlame): study design and methodology of a multicentre randomized, placebo-controlled trial

Neuroinflammation has been proposed to impact symptomatology in patients with schizophrenia spectrum disorders. While previous studies have shown equivocal effects of treatments with add-on anti-inflammatory drugs such as Aspirin, N-acetylcysteine and Celecoxib, none have used a subset of prospectively recruited patients exhibiting an inflammatory profile. The aim of the study is to evaluate the efficacy and safety as well as the cost-effectiveness of a treatment with 400 mg Celecoxib added to an ongoing antipsychotic treatment in patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. The “Add-on Celecoxib treatment in patients with schizophrenia spectrum disorders and inflammatory cytokine profile trial (TargetFlame)” is a multicentre randomized, placebo-controlled phase III investigator-initiated clinical trial with the following two arms: patients exhibiting an inflammatory profile receiving either add-on Celecoxib 400 mg/day or add-on placebo. A total of 199 patients will be assessed for eligibility by measuring blood levels of three pro-inflammatory cytokines, and 109 patients with an inflammatory profile, i.e. inflamed, will be randomized, treated for 8 weeks and followed-up for additional four months. The primary endpoint will be changes in symptom severity as assessed by total Positive and Negative Syndrome Scale (PANSS) score changes from baseline to week 8. Secondary endpoints include various other measures of psychopathology and safety. Additional health economic analyses will be performed. TargetFlame is the first study aimed at evaluating the efficacy, safety and cost-effectiveness of the antiphlogistic agent Celecoxib in a subset of patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. With TargetFlame, we intended to investigate a novel precision medicine approach towards anti-inflammatory antipsychotic treatment augmentation using drug repurposing.

Clinical trial registration:http://www.drks.de/DRKS00029044 and https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00029044

Abnormal cortisol profile during psychosocial stress among patients with schizophrenia in a Chinese population

Accumulating evidence suggests that hypothalamic-pituitary-adrenal axis dysfunction might play an important role in the pathophysiology of schizophrenia. The aim of this study was to explore the cortisol response to psychological stress in patients with schizophrenia. In this study, patients with schizophrenia (n = 104) and healthy volunteers (n = 59) were asked to complete psychological stress challenge tasks, which included the Paced Auditory Serial Addition Task and Mirror-Tracing Persistence Task, and pre- and post-task saliva samples were collected to measure cortisol levels. Emotions and psychopathology were assessed by the Positive and Negative Affect Schedule and Positive and Negative Syndrome Scale. The results showed (1) that the cortisol response and negative emotions in patients with schizophrenia differed significantly from those in healthy volunteers, (2) there were significant interactions between the sampling time and diagnosis for saliva cortisol levels, (3) there were significant interactions between the scoring time and diagnosis for the negative affect score of the PANAS, and (4) the changes in salivary cortisol levels and negative affect scores before and after the psychological stress challenge tasks were not correlated with clinical symptoms in patients with schizophrenia. These findings indicated an abnormal cortisol profile in patients with schizophrenia, which might be a biological characteristic of the disease.

Amisulpride augmentation therapy improves cognitive performance and psychopathology in clozapine-resistant treatment-refractory schizophrenia: a 12-week randomized, double-blind, placebo-controlled trial

BACKGROUND

Although clozapine is an effective option for treatment-resistant schizophrenia (TRS), there are still 1/3 to 1/2 of TRS patients who do not respond to clozapine. The main purpose of this randomized, double-blind, placebo-controlled trial was to explore the amisulpride augmentation efficacy on the psychopathological symptoms and cognitive function of clozapine-resistant treatment-refractory schizophrenia (CTRS) patients.

METHODS

A total of 80 patients were recruited and randomly assigned to receive initial clozapine plus amisulpride (amisulpride group) or clozapine plus placebo (placebo group). Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Clinical Global Impression (CGI) scale scores, Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Treatment Emergent Symptom Scale (TESS), laboratory measurements, and electrocardiograms (ECG) were performed at baseline, at week 6, and week 12.

RESULTS

Compared with the placebo group, amisulpride group had a lower PANSS total score, positive subscore, and general psychopathology subscore at week 6 and week 12 (P_Bonferroni < 0.01). Furthermore, compared with the placebo group, the amisulpride group showed an improved RBANS language score at week 12 (P_Bonferroni < 0.001). Amisulpride group had a higher treatment response rate (P = 0.04), lower scores of CGI severity and CGI efficacy at week 6 and week 12 than placebo group (P_Bonferroni < 0.05). There were no differences between the groups in body mass index (BMI), corrected QT (QTc) intervals, and laboratory measurements. This study demonstrates that amisulpride augmentation therapy can safely improve the psychiatric symptoms and cognitive performance of CTRS patients.

CONCLUSION

This study indicates that amisulpride augmentation therapy has important clinical significance for treating CTRS to improve clinical symptoms and cognitive function with tolerability and safety. Trial registration Clinicaltrials.gov identifier- NCT03652974. Registered August 31, 2018, https://clinicaltrials.gov/ct2/show/NCT03652974.

Hair cortisol levels in schizophrenia and metabolic syndrome

AIM

Individuals with schizophrenia demonstrate higher rates of metabolic syndrome (MetS) than the general population. Hair cortisol concentrations (HCC) reflect longer-term cortisol secretion and can provide additional insights into the role of the hypothalamic pituitary adrenal (HPA) axis in schizophrenia and co-occurring MetS.

METHODS

In a case-control study of 16 patients with schizophrenia (11 first episode psychosis [FEP] and 5 chronic) and 21 controls hair samples, representing a 3-month retrospective window of cortisol, were collected and analysed utilizing liquid chromatography tandem mass spectrometry. We investigated whether schizophrenia and MetS co-occurrence were associated with HCC utilizing multivariate regression models. We also explored the longitudinal trajectory of HCC in FEP patients by conducting a mixed models analysis.

RESULTS

At baseline HCC were significantly lower (Cohen's d = 0.88) in patients with schizophrenia than in controls (p = .014). HCC increased from baseline to month-12 in FEP patients compared to controls, demonstrating a trend towards significance (p = .097). MetS was not associated with HCC at baseline, but HCC increased significantly from baseline to month-12 in relation to MetS (p = .037).

CONCLUSIONS

In a subgroup of schizophrenia patients, psychosis may be associated with a blunted HPA axis with lower long-term cortisol output. MetS was associated with an increase in HCC and elevated cortisol levels observed in schizophrenia may be related to increased rates of MetS in schizophrenia patients.

Effect of risperidone on serum IL-6 levels in individuals with schizophrenia: a systematic review and meta-analysis

BACKGROUND

Risperidone has been significant correlated with a direct effect of interleukin-6 (IL-6) levels in patients with schizophrenia. This fact allows the opportunity to link the probable immunomodulatory effect of antipsychotic medication. Specially, a proper functioning of IL-6 pathway plays a potential role in the treatment or development of schizophrenia.

OBJECTIVE

Our primary aim was to perform a systematic review and meta-analysis to determine the effect of risperidone on IL-6 levels in individuals with schizophrenia.

METHODS

Studies were identified through a systematic search using PubMed, Scopus, and Web of Science databases. The articles found were subjected to the inclusion and exclusion criteria; then, the mean and standardised differences were extracted to calculate the standardised mean differences using the CMA software.

RESULTS

IL-6 levels in individuals with schizophrenia were compared before and after receiving risperidone as treatment. Increased levels of IL-6 levels were observed in individuals with schizophrenia who received risperidone (point estimate 0.249, lower limit 0.042, upper limit 0.455, p-value 0.018). In the Asian population sub-analysis, no statistically significant differences were observed (point estimate 0.103, lower limit -0.187, upper limit 0.215, p value 0.890). When we compared individuals with schizophrenia to the control groups, a significant increase of IL-6 levels was observed in the group with schizophrenia (point estimate 0.248, lower limit 0.024, upper limit 0.472, p-value 0.30).

CONCLUSIONS

Risperidone appears to play an important role in IL-6 levels in schizophrenia. Potential implications of increased IL-6 levels in people with schizophrenia should be considered in future studies.KEY POINTSIncreased levels of IL-6 levels were observed in individuals with schizophrenia who received risperidone.Risperidone appears to play an important role in IL-6 levels in schizophrenia.This study could serve for future research focussed on IL-6.

Immuno-metabolic profile of patients with psychotic disorders and metabolic syndrome. Results from the FACE-SZ cohort

Background

Metabolic syndrome (MetS) is a highly prevalent and harmful medical disorder often comorbid with psychosis where it can contribute to cardiovascular complications. As immune dysfunction is a key shared component of both MetS and schizophrenia (SZ), this study investigated the relationship between immune alterations and MetS in patients with SZ, whilst controlling the impact of confounding clinical characteristics including psychiatric symptoms and comorbidities, history of childhood maltreatment and psychotropic treatments.

Method

A total of 310 patients meeting DSM-IV criteria for SZ or schizoaffective disorders (SZA), with or without MetS, were systematically assessed and included in the FondaMental Advanced Centers of Expertise for Schizophrenia (FACE-SZ) cohort. Detailed clinical characteristics of patients, including psychotic symptomatology, psychiatric comorbidities and history of childhood maltreatment were recorded and the serum levels of 18 cytokines were measured. A penalized regression method was performed to analyze associations between inflammation and MetS, whilst controlling for confounding factors.

Results

Of the total sample, 25% of patients had MetS. Eight cytokines were above the lower limit of detection (LLOD) in more than 90% of the samples and retained in downstream analysis. Using a conservative Variable Inclusion Probability (VIP) of 75%, we found that elevated levels of interleukin (IL)-6, IL-7, IL-12/23 p40 and IL-16 and lower levels of tumor necrosis factor (TNF)-α were associated with MetS. As for clinical variables, age, sex, body mass index (BMI), diagnosis of SZ (not SZA), age at the first episode of psychosis (FEP), alcohol abuse, current tobacco smoking, and treatment with antidepressants and anxiolytics were all associated with MetS.

Conclusion

We have identified five cytokines associated with MetS in SZ suggesting that patients with psychotic disorders and MetS are characterized by a specific “immuno-metabolic” profile. This may help to design tailored treatments for this subgroup of patients with both psychotic disorders and MetS, taking one more step towards precision medicine in psychiatry.

Childhood Trauma Associations With the Interpersonal Psychological Theory of Suicide and Social Cognitive Biases in Psychotic Disorders

Childhood trauma (CT) is associated with suicidal ideation and behaviors (SI/SB) in people with psychosis. The interpersonal psychological theory of suicide (IPTS) suggests that there are four factors that increase suicide risk: thwarted belongingness, perceived burdensomeness, acquired capacity for suicide, and hopelessness. The IPTS constructs and social cognitive biases are associated with SI/SB in psychotic disorders. However, the role of CT in IPTS constructs and social cognitive biases has not been examined in psychosis. In an outpatient community sample of persons with psychotic disorders (N = 96) assessed with the Childhood Trauma Questionnaire, the aims of this study were to a) evaluate rates of CT in this sample, b) determine the relationship between CT types and lifetime SI/SB, and c) explore the relationship between CT types, IPTS constructs, and social cognitive biases. All participants reported experiencing CT. Emotional abuse was associated with greater SI severity and higher rates of lifetime suicide attempts, as well as with greater perceived burdensomeness and more severe negative social cognitive biases. Other CT types were minimally associated with SI/SB or IPST constructs; hopelessness was not associated. Overall, negative interpersonal beliefs and social cognitive biases may explain how CT increases suicide risk in psychosis.

Dynamics of views on different aspects of schizophrenia (Narrative Literature Review)

Как известно, шизофрения остается во многом неясным психическим расстройством, являющимся значительным социальным и экономическим бременем. Поэтому обзоры литературы, охватывающие основные аспекты этиологии, диагностики и диагностических ошибок в разные временные периоды, представляются актуальными. В статье приведены данные анализа более 200 отечественных и зарубежных работ по указанным аспектам шизофрении, преимущественно за последние 10 лет, а также имеющих важное историческое значение. Обзор литературы по вопросам этиологии и диагностики шизофрении может способствовать вниманию ученых к тем или иным результатам исследований на новом концептуальном и методическом этапе. При этом качественные изменения в понимании шизофрении и расстройств шизофренического спектра способствуют развитию инновационных технологий в психиатрии, что важно для науки и практики данной дисциплины.

Correlation Between the Different Types of Antipsychotics and Serum Cortisol, Dehidroepiandrosterone Sulfat and their Ratio in Schizophrenia

Background: Evidence for disturbances in HPA activation and abnormal HPA regulatory mechanisms in schizophrenia is accumulating. Aim: To compare serum levels of cortisol, DHEA-S and their ratio between patients with schizophrenia and healthy controls and among patients before and after treatment with different types of antipsychotics. Material and methods: In this clinical prospective study, 60 patients with schizophrenia and 40 healthy age and sex matched control subjects were included. All patients experienced an acute exacerbation of the illness (PANSS: P1 and P3 ≥ 4). Clinical evaluation of patients was performed using the Positive and Negative Symptom Scale. A questionnaire for socio-demographic and clinical data collection was used. Serum levels of cortisol, DHEA-S and their ratio were measured at baseline in all participants and after 3 and 6 weeks, respectively, of the antipsychotic treatment with different types of antipsychotics in patients with schizophrenia. Results: Patients with schizophrenia had significantly higher serum cortisol and DHEA-S levels in comparison to the control group. There was no significant difference in serum levels of cortisol, DHEA-S and their ratio between patients treated with different types of antipsychotics (typical/atypical). Serum levels of the analyzed hormones significantly reduce during the 6-week period of examination in both subgroups treated with different types of antipsychotics. Conclusion: Elevated serum cortisol and DHEA-S in schizophrenic patients might be associated with their role in the pathophysiology of the disorder. There is no significant difference in serum levels of cortisol, DHEA-S and their ratio among the patients treated with different types of antipsychotics.

Trauma and resistance to antipsychotic treatment in schizophrenia: A narrative review

This review explored whether trauma exposure is associated with poorer response to antipsychotic treatment in schizophrenia patients. A systematic search identified eight studies, of which five reported an association between trauma and non-remission of psychotic symptoms (n = 4) or treatment-resistant schizophrenia (TRS, n = 1). Although evidence supporting the link between trauma and resistance to antipsychotic treatment is scarce, trauma history should be systematically investigated in all persons with TRS, as there is a growing body of evidence showing that schizophrenia patients benefit from therapies for post-traumatic symptoms.