Altering the course of schizophrenia: progress and perspectives. Nat Rev Drug Discov. 2016;15:485-515. [PMID: 26939910 DOI: 10.1038/nrd.2016.28]

A novel blood-based epigenetic biosignature in first-episode schizophrenia patients through automated machine learning

Schizophrenia (SCZ) is a chronic, severe, and complex psychiatric disorder that affects all aspects of personal functioning. While SCZ has a very strong biological component, there are still no objective diagnostic tests. Lately, special attention has been given to epigenetic biomarkers in SCZ. In this study, we introduce a three-step, automated machine learning (AutoML)-based, data-driven, biomarker discovery pipeline approach, using genome-wide DNA methylation datasets and laboratory validation, to deliver a highly performing, blood-based epigenetic biosignature of diagnostic clinical value in SCZ. Publicly available blood methylomes from SCZ patients and healthy individuals were analyzed via AutoML, to identify SCZ-specific biomarkers. The methylation of the identified genes was then analyzed by targeted qMSP assays in blood gDNA of 30 first-episode drug-naïve SCZ patients and 30 healthy controls (CTRL). Finally, AutoML was used to produce an optimized disease-specific biosignature based on patient methylation data combined with demographics. AutoML identified a SCZ-specific set of novel gene methylation biomarkers including IGF2BP1, CENPI, and PSME4. Functional analysis investigated correlations with SCZ pathology. Methylation levels of IGF2BP1 and PSME4, but not CENPI were found to differ, IGF2BP1 being higher and PSME4 lower in the SCZ group as compared to the CTRL group. Additional AutoML classification analysis of our experimental patient data led to a five-feature biosignature including all three genes, as well as age and sex, that discriminated SCZ patients from healthy individuals [AUC 0.755 (0.636, 0.862) and average precision 0.758 (0.690, 0.825)]. In conclusion, this three-step pipeline enabled the discovery of three novel genes and an epigenetic biosignature bearing potential value as promising SCZ blood-based diagnostics.

Dynamic and transdiagnostic risk calculator based on Natural Language Processing for the prediction of psychosis in secondary mental health care: development and internal-external validation cohort study

BACKGROUND

Automatic transdiagnostic risk calculators can improve detection of individuals at risk of psychosis. However, they rely on a single point in time assessment and can be refined with dynamic modelling techniques that account for changes in risk over time.

METHODS

We included n=158,139 patients (n=5,007 events) receiving a first index diagnosis of a non-organic and non-psychotic mental disorder within Electronic Health Records from the SLaM NHS Foundation Trust between 01/01/2008 and 10/08/2021. A dynamic Cox landmark model was developed to estimate the 2-year risk of developing psychosis according to TRIPOD statement. The dynamic model included 24 predictors extracted at nine landmark points (baseline, 0, 6, 12, 24, 30, 36, 42, and 48 months): three demographic, one clinical, and 20 Natural Language Processing (NLP) based symptom and substance use predictors. Performance was compared to a static Cox regression model with all predictors assessed at baseline only, indexed via discrimination (C-index), calibration (calibration plots), and potential clinical utility (decision curves) in internal-external validation.

RESULTS

The dynamic model improves discrimination performance compared to the static model at baseline (dynamic: C-index=0.9; static: C-index=0.87) to the final landmark point (dynamic: C-index=0.79; static: C-index=0.76). The dynamic model was also significantly better calibrated (calibration slope=0.97-1.1) than the static model at later landmark points (≥24 months). Net benefit was higher in the dynamic compared to the static model at later landmark points (≥24 months).

CONCLUSION

These findings suggest that dynamic prediction models can improve detection of individuals at risk for psychosis in secondary mental health care.

Recapitulation of Perturbed Striatal Gene Expression Dynamics of Donors' Brains With Ventral Forebrain Organoids Derived From the Same Individuals With Schizophrenia

OBJECTIVE

Schizophrenia is a brain disorder that originates during neurodevelopment and has complex genetic and environmental etiologies. Despite decades of clinical evidence of altered striatal function in affected patients, studies examining its cellular and molecular mechanisms in humans are limited. To explore neurodevelopmental alterations in the striatum associated with schizophrenia, the authors established a method for the differentiation of induced pluripotent stem cells (iPSCs) into ventral forebrain organoids (VFOs).

METHODS

VFOs were generated from postmortem dural fibroblast-derived iPSCs of four individuals with schizophrenia and four neurotypical control individuals for whom postmortem caudate genotypes and transcriptomic data were profiled in the BrainSeq neurogenomics consortium. Individuals were selected such that the two groups had nonoverlapping schizophrenia polygenic risk scores (PRSs).

RESULTS

Single-cell RNA sequencing analyses of VFOs revealed differences in developmental trajectory between schizophrenia and control individuals in which inhibitory neuronal cells from the patients exhibited accelerated maturation. Furthermore, upregulated genes in inhibitory neurons in schizophrenia VFOs showed a significant overlap with upregulated genes in postmortem caudate tissue of individuals with schizophrenia compared with control individuals, including the donors of the iPSC cohort.

CONCLUSIONS

The findings suggest that striatal neurons derived from high-PRS individuals with schizophrenia carry abnormalities that originated during early brain development and that the VFO model can recapitulate disease-relevant cell type-specific neurodevelopmental phenotypes in a dish.

Aberrant connectivity in the hippocampus, bilateral insula and temporal poles precedes treatment resistance in first-episode psychosis: a prospective resting-state functional magnetic resonance imaging study with connectivity concordance mapping

Functional connectivity resting-state functional magnetic resonance imaging has been proposed to predict antipsychotic treatment response in schizophrenia. However, only a few prospective studies have examined baseline resting-state functional magnetic resonance imaging data in drug-naïve first-episode schizophrenia patients with regard to subsequent treatment response. Data-driven approaches to conceptualize and measure functional connectivity patterns vary broadly, and model-free, voxel-wise, whole-brain analysis techniques are scarce. Here, we apply such a method, called connectivity concordance mapping to resting-state functional magnetic resonance imaging data acquired from an Asian sample (n = 60) with first-episode psychosis, prior to pharmaceutical treatment. Using a longitudinal design, 12 months after the resting-state functional magnetic resonance imaging, we measured and classified patients into two groups based on psychometric testing: treatment responsive and treatment resistant. Next, we compared the two groups' connectivity concordance maps that were derived from the resting-state functional magnetic resonance imaging data at baseline. We have identified consistently higher functional connectivity in the treatment-resistant group in a network including the left hippocampus, bilateral insula and temporal poles. These data-driven novel findings can help researchers to consider new regions of interest and facilitate biomarker development in order to identify treatment-resistant schizophrenia patients early, in advance of treatment and at the time of their first psychotic episode.

Advances in electroactive bioscaffolds for repairing spinal cord injury

Spinal cord injury (SCI) is a devastating neurological disorder, leading to loss of motor or somatosensory function, which is the most challenging worldwide medical problem. Re-establishment of intact neural circuits is the basis of spinal cord regeneration. Considering the crucial role of electrical signals in the nervous system, electroactive bioscaffolds have been widely developed for SCI repair. They can produce conductive pathways and a pro-regenerative microenvironment at the lesion site similar to that of the natural spinal cord, leading to neuronal regeneration and axonal growth, and functionally reactivating the damaged neural circuits. In this review, we first demonstrate the pathophysiological characteristics induced by SCI. Then, the crucial role of electrical signals in SCI repair is introduced. Based on a comprehensive analysis of these characteristics, recent advances in the electroactive bioscaffolds for SCI repair are summarized, focusing on both the conductive bioscaffolds and piezoelectric bioscaffolds, used independently or in combination with external electronic stimulation. Finally, thoughts on challenges and opportunities that may shape the future of bioscaffolds in SCI repair are concluded.

Brain-derived neurotrophic factor levels across psychiatric disorders: A systemic review and network meta-analysis

As an important neurotrophic factor in the central nervous system, Brain-derived Neurotrophic Factor (BDNF) has been implicated in the pathophysiology of psychiatric disorders in many studies. However, its value as a biomarker for the diagnosis and differential diagnosis of mental disorders is still controversial, and its change patterns among different mental disorders have not been compared. We conducted a network meta-analysis of BDNF levels in different psychiatric disorders including schizophrenia(SCZ), major depressive disorder(MDD), bipolar disorder(BD), panic disorder(PD), post-traumatic stress disorder(PTSD), obsessive-compulsive disorder(OCD), generalized anxiety disorder(GAD) and insomnia. Studies were identified by searching electronic databases through 31/05/2023. BDNF levels decreased in patients with BD, MDD, OCD, PD, SCZ compared with controls, while significantly increased in patients with PTSD. According to the network meta-analysis, BDNF levels were significantly decreased in MDD and SCZ compared with BD (-2.6, 95% CIs [-5.32 to -0.15] and - 2.68 95% CIs [-5.18 to -0.23] respectively). However, in the traditional meta-analysis, there was a trend towards lower BDNF levels in SCZ compared to BD, with no significant difference (SMD = -0.20, 95% CIs [-0.49 to 0.08]). In conclusion, abnormal BDNF levels have been found in psychiatric disorders, and the changes in peripheral BDNF levels in patients with psychiatric disorders were reconfirmed in this study, which suggests BDNF exhibits promising clinical utility and may hold diagnostic value in distinguishing between MDD and BD.

Increased hippocampal blood flow in people at clinical high risk for psychosis and effects of cannabidiol

BACKGROUND

Hippocampal hyperperfusion has been observed in people at Clinical High Risk for Psychosis (CHR), is associated with adverse longitudinal outcomes and represents a potential treatment target for novel pharmacotherapies. Whether cannabidiol (CBD) has ameliorative effects on hippocampal blood flow (rCBF) in CHR patients remains unknown.

METHODS

Using a double-blind, parallel-group design, 33 CHR patients were randomized to a single oral 600 mg dose of CBD or placebo; 19 healthy controls did not receive any drug. Hippocampal rCBF was measured using Arterial Spin Labeling. We examined differences relating to CHR status (controls v. placebo), effects of CBD in CHR (placebo v. CBD) and linear between-group relationships, such that placebo > CBD > controls or controls > CBD > placebo, using a combination of hypothesis-driven and exploratory wholebrain analyses.

RESULTS

Placebo-treated patients had significantly higher hippocampal rCBF bilaterally (all pFWE<0.01) compared to healthy controls. There were no suprathreshold effects in the CBD v. placebo contrast. However, we found a significant linear relationship in the right hippocampus (pFWE = 0.035) such that rCBF was highest in the placebo group, lowest in controls and intermediate in the CBD group. Exploratory wholebrain results replicated previous findings of hyperperfusion in the hippocampus, striatum and midbrain in CHR patients, and provided novel evidence of increased rCBF in inferior-temporal and lateral-occipital regions in patients under CBD compared to placebo.

CONCLUSIONS

These findings suggest that hippocampal blood flow is elevated in the CHR state and may be partially normalized by a single dose of CBD. CBD therefore merits further investigation as a potential novel treatment for this population.

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.

Mapping the landscape: a bibliometric analysis of resting-state fMRI research on schizophrenia over the past 25 years

Schizophrenia, a multifaceted mental disorder characterized by disturbances in thought, perception, and emotion, has been extensively investigated through resting-state fMRI, uncovering changes in spontaneous brain activity among those affected. However, a bibliometric examination regarding publication trends in resting-state fMRI studies related to schizophrenia is lacking. This study obtained relevant publications from the Web of Science Core Collection spanning the period from 1998 to 2022. Data extracted from these publications included information on countries/regions, institutions, authors, journals, and keywords. The collected data underwent analysis and visualization using VOSviewer software. The primary analyses included examination of international and institutional collaborations, authorship patterns, co-citation analyses of authors and journals, as well as exploration of keyword co-occurrence and temporal trend networks. A total of 859 publications were retrieved, indicating an overall growth trend from 1998 to 2022. China and the United States emerged as the leading contributors in both publication outputs and citations, with Central South University and the University of New Mexico being identified as the most productive institutions. Vince D. Calhoun had the highest number of publications and citation counts, while Karl J. Friston was recognized as the most influential author based on co-citations. Key journals such as Neuroimage, Schizophrenia Research, Schizophrenia Bulletin, and Biological Psychiatry played pivotal roles in advancing this field. Recent popular keywords included support vector machine, antipsychotic medication, transcranial magnetic stimulation, and related terms. This study systematically synthesizes the historical development, current status, and future trends in resting-state fMRI research in schizophrenia, offering valuable insights for future research directions.

Review on allosteric modulators of dopamine receptors so far

Background Contemporary research is predominantly directed towards allosteric modulators, a class of compounds designed to interact with specific sites distinct from the orthosteric site on G protein-coupled receptors. These allosteric modulators play a pivotal role in influencing diverse pharmacological effects, such as agonism/inverse agonism, efficacy modulation, and affinity modulation. One particularly intriguing aspect is the demonstrated capacity of allosteric modulation to enhance drug selectivity for therapeutic purposes, potentially leading to a reduction in serious side effects associated with traditional approaches. Allosteric ligands, a majority of which fall into the categories of negative allosteric modulators or positive allosteric modulators, exhibit the unique ability to either diminish or enhance the effects of endogenous ligands. Negative allosteric modulators weaken the response, while positive allosteric modulators intensify it. Additionally, silent allosteric modulators represent a distinct class that neither activates nor blocks the effects of endogenous ligands, adding complexity to the spectrum of allosteric modulation. In the broader context of central nervous system disorders, allosteric modulation takes center stage, particularly in the realm of dopamine receptors specifically, D1, D2, and D3 receptors. These receptors hold immense therapeutic potential for a range of conditions spanning neurodegenerative disorders to neurobehavioral and psychiatric disorders. The intricate modulation of dopamine receptors through allosteric mechanisms offers a nuanced and versatile approach to drug development. As research endeavors continue to unfold, the exploration of allosteric modulation stands as a promising frontier, holding the potential to reshape the landscape of drug discovery and therapeutic interventions in the field of neurology and psychiatry.

TLR/mTOR inflammatory signaling pathway: novel insight for the treatment of schizophrenia

The Toll-like receptor (TLR)/mammalian target of rapamycin (mTOR) signaling pathway is involved in the intracellular regulation of protein synthesis, specifically the ones that mediate neuronal morphology and facilitate synaptic plasticity. The activity of TLR/mTOR signaling has been disrupted, leading to neurodevelopment and deficient synaptic plasticity, which are the main symptoms of schizophrenia. The TLR receptor activates the mTOR signaling pathway and increases the elevation of inflammatory cytokines. Interleukin (IL)-6 is the most commonly altered cytokine, while IL-1, tumor necrosis factor, and interferon (IFN) also lead to SCZ. Anti-inflammatory and anti-oxidative agents such as celecoxib, aspirin, minocycline, and omega-3 fatty acids have shown efficiency against SCZ. As a result, inhibition of the inflammatory process could be suggested for the treatment of SCZ. So mTOR/TLR blockers represent the treatment of SCZ due to their inflammatory consequences. The objective of the present work was to find a novel anti-inflammatory agent that may block the mTOR/TLR inflammatory signaling pathways and might pave the way for the treatment of neuroinflammatory SCZ. Data were collected from experimental and clinical studies published in English between 1998 and October 2022 from Google Scholar, PubMed, Scopus, and the Cochrane library.

Schizophrenia-relevant social, attentional and cognitive traits in female RHA vs. RLA rats: Effects of neonatal handling

The Roman high- (RHA) and low-avoidance (RLA) rats were bidirectionally selected and bred for, respectively, their rapid vs. extremely poor acquisition in the two-way active avoidance task. Consistent between-strain neurobehavioural differences have been found in anxiety- and stress-linked traits, as well as in schizophrenia-related phenotypes. RLAs display enhanced anxious- and stress-related phenotypes, whereas RHA rats show impulsivity, hyperactivity and attention/cognition-related impairments. Many of these typical behavioural phenotypes have been reported to be positively modulated by environmental treatments such as neonatal handling (NH). However, most studies on the Roman rat strains have been carried out in males. Thus, the present study for the first time focused on the joint evaluation of differences in novel object exploration (NOE), social interaction (SI), prepulse inhibition of the startle response (PPI), and cognitive performance and flexibility in various spatial tasks (using the Morris water maze, MWM) in females of both Roman rat strains. We also aimed at evaluating the long-lasting effects of NH treatment on the RHA vs. RLA profiles in these tests/tasks. Results show that anxiety-related behavior, as measured by the NOE test and self-grooming in the SI test, was increased in RLA rats, and dramatically reduced by NH. In the SI test RLA rats displayed diminished social interaction, which was rescued by NH. RHA females exhibited a deficit of PPI, which was not affected by NH. Spatial tasks in the MWM showed impairments of working memory, reference learning/memory and spatial reversal learning (i.e., cognitive flexibility) in RHA females. Spatial reference learning and cognitive flexibility (i.e., reversal task) showed some improvement in rats (mainly in RHAs) that had received NH during the first three weeks of life. With the exception of the SI test, the pattern of differences between female RHA vs. RLA profiles was overall consistent with what has previously been found in males of both strains, and NH treatment was able to enduringly improve some emotion-related and (spatial) cognitive outcomes in both strains.

The role of glial cells in mental illness: a systematic review on astroglia and microglia as potential players in schizophrenia and its cognitive and emotional aspects

Schizophrenia is a complex and severe mental disorder that affects approximately 1% of the global population. It is characterized by a wide range of symptoms, including delusions, hallucinations, disorganized speech and behavior, and cognitive impairment. Recent research has suggested that the immune system dysregulation may play a significant role in the pathogenesis of schizophrenia, and glial cells, such as astroglia and microglia known to be involved in neuroinflammation and immune regulation, have emerged as potential players in this process. The aim of this systematic review is to summarize the glial hallmarks of schizophrenia, choosing as cellular candidate the astroglia and microglia, and focusing also on disease-associated psychological (cognitive and emotional) changes. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, Scopus, and Web of Science for articles that investigated the differences in astroglia and microglia in patients with schizophrenia, published in the last 5 years. The present systematic review indicates that changes in the density, morphology, and functioning of astroglia and microglia may be involved in the development of schizophrenia. The glial alterations may contribute to the pathogenesis of schizophrenia by dysregulating neurotransmission and immune responses, worsening cognitive capabilities. The complex interplay of astroglial and microglial activation, genetic/epigenetic variations, and cognitive assessments underscores the intricate relationship between biological mechanisms, symptomatology, and cognitive functioning in schizophrenia.

We need to talk: a qualitative inquiry into pathways to care for young men at ultra-high risk for psychosis

Introduction

It is known from the literature that men are slower to seek help and staying engaged in mental health care compared to women. Seeing that in psychosis, men more often than women have insidious onsets but also a more malign illness course, it is important to find ways to improve timely help-seeking. The aim of this study was to explore barriers and facilitators for help-seeking in young male persons struggling with early signs of psychosis.

Methods

Qualitative interviews with nine young men who suffer from a first episode of psychosis or psychosis risk symptoms.

Results

Male stereotypical ideals, significant others, and knowledge of symptoms and where to get help as well characteristics of symptom trajectories appeared to be important determinants of help-seeking behavior.

Discussion

Interviews indicated that help-seeking in the participants was delayed first, because of reluctancy to disclose distress and second, because significant others were unable to accurately recognize symptoms. Information, awareness, and easy access to care remain important in early detection and intervention in psychosis and psychosis risk. However, more emphasis should be placed on de-stigmatizing mental health problems in men and aiming information specifically at them.

Retina as a potential biomarker in schizophrenia spectrum disorders: a systematic review and meta-analysis of optical coherence tomography and electroretinography

INTRODUCTION

Abnormal findings on optical coherence tomography (OCT) and electroretinography (ERG) have been reported in participants with schizophrenia spectrum disorders (SSDs). This study aims to reveal the pooled standard mean difference (SMD) in retinal parameters on OCT and ERG among participants with SSDs and healthy controls and their association with demographic characteristics, clinical symptoms, smoking, diabetes mellitus, and hypertension.

METHODS

Using PubMed, Scopus, Web of Science, and PSYNDEX, we searched the literature from inception to March 31, 2023, using specific search terms. This study was registered with PROSPERO (CRD4202235795) and conducted according to PRISMA 2020.

RESULTS

We included 65 studies in the systematic review and 44 in the meta-analysis. Participants with SSDs showed thinning of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer- inner plexiform cell layer, and retinal thickness in all other segments of the macula. A meta-analysis of studies that excluded SSD participants with diabetes and hypertension showed no change in results, except for pRNFL inferior and nasal thickness. Furthermore, a significant difference was found in the pooled SMD of pRNFL temporal thickness between the left and right eyes. Meta-regression analysis revealed an association between retinal thinning and duration of illness, positive and negative symptoms. In OCT angiography, no differences were found in the foveal avascular zone and superficial layer foveal vessel density between SSD participants and controls. In flash ERG, the meta-analysis showed reduced amplitude of both a- and b-waves under photopic and scotopic conditions in SSD participants. Furthermore, the latency of photopic a-wave was significantly shorter in SSD participants in comparison with HCs.

DISCUSSION

Considering the prior report of retinal thinning in unaffected first-degree relatives and the results of the meta-analysis, the findings suggest that retinal changes in SSDs have both trait and state aspects. Future longitudinal multimodal retinal imaging studies are needed to clarify the pathophysiological mechanisms of these changes and to clarify their utility in individual patient monitoring efforts.

TrkB receptor interacts with mGlu2 receptor and mediates antipsychotic-like effects of mGlu2 receptor activation in the mouse

Metabotropic glutamate receptor 2 (mGlu2) attracts particular attention as a possible target for a new class of antipsychotics. However, the signaling pathways transducing the effects of mGlu2 in the brain remain poorly characterized. Here, we addressed this issue by identifying native mGlu2 interactome in mouse prefrontal cortex. Nanobody-based affinity purification and mass spectrometry identified 149 candidate mGlu2 partners, including the neurotrophin receptor TrkB. The later interaction was confirmed both in cultured cells and prefrontal cortex. mGlu2 activation triggers phosphorylation of TrkB on Tyr816 in primary cortical neurons and prefrontal cortex. Reciprocally, TrkB stimulation enhances mGlu2-operated Gi/o protein activation. Furthermore, TrkB inhibition prevents the rescue of behavioral deficits by glutamatergic antipsychotics in phencyclidine-treated mice. Collectively, these results reveal a cross-talk between TrkB and mGlu2, which is key to the behavioral response to glutamatergic antipsychotics.

Divergent epigenetic responses to perinatal asphyxia in severe mental disorders

Epigenetic modifications influenced by environmental exposures are molecular sources of phenotypic heterogeneity found in schizophrenia and bipolar disorder and may contribute to shared etiopathogenetic mechanisms of these two disorders. Newborns who experienced perinatal asphyxia have suffered reduced oxygen delivery to the brain around the time of birth, which increases the risk of later psychiatric diagnosis. This study aimed to investigate DNA methylation in blood cells for associations with a history of perinatal asphyxia, a neurologically harmful condition occurring within the biological environment of birth. We utilized prospective data from the Medical Birth Registry of Norway to identify incidents of perinatal asphyxia in 643 individuals with schizophrenia or bipolar disorder and 676 healthy controls. We performed an epigenome wide association study to distinguish differentially methylated positions associated with perinatal asphyxia. We found an interaction between methylation and exposure to perinatal asphyxia on case-control status, wherein having a history of perinatal asphyxia was associated with an increase of methylation in healthy controls and a decrease of methylation in patients on 4 regions of DNA important for brain development and function. The differentially methylated regions were observed in genes involved in oligodendrocyte survival and axonal myelination and functional recovery (LINGO3); assembly, maturation and maintenance of the brain (BLCAP;NNAT and NANOS2) and axonal transport processes and neural plasticity (SLC2A14). These findings are consistent with the notion that an opposite epigenetic response to perinatal asphyxia, in patients compared with controls, may contribute to molecular mechanisms of risk for schizophrenia and bipolar disorder.

Pro-social and pro-cognitive effects of LIT-001, a novel oxytocin receptor agonist in a neurodevelopmental model of schizophrenia

Social and cognitive dysfunctions are the most persistent symptoms of schizophrenia. Since oxytocin (OXT) is known to play a role in social functions and modulates cognitive processes, we investigated the effects of a novel, nonpeptide, selective OXT receptor agonist, LIT-001, in a neurodevelopmental model of schizophrenia. Administration of methylazoxymethanol acetate (MAM; 22 mg/kg) on the 17th day of rat pregnancy is known to cause developmental disturbances of the brain, which lead to schizophrenia-like symptomatology in the offspring. Here, we examined the effects of acutely administered LIT-001 (1, 3, and 10 mg/kg) in MAM-exposed males and females on social behaviour, communication and cognition. We report that MAM-treated adult male and female rats displayed reduced social behaviour, ultrasonic communication and novel object recognition test performance. LIT-001 partially reversed these deficits, increasing the total social interaction time and the number of 'positive', highly-modulated 50 kHz ultrasonic calls in male rats. The compound ameliorated MAM-induced deficits in object discrimination in both sexes. Present results confirm the pro-social activity of LIT-001 and demonstrate its pro-cognitive effects following acute administration.

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 Promotion of Mental Health and Prevention of First-Episode Psychosis: A Pilot and Feasibility Non-Randomised Clinical Trial

BACKGROUND

Mental-health-related stigma prevents active help seeking and therefore early therapeutic approaches and the recovery of functionality. National and international agencies recommend the implementation of prevention and mental health promotion programs that support the elimination of stigma in the classroom, since most mental health problems usually start in the adolescent stage. In view of the evidence that teachers present stigmatizing attitudes towards mental health, it has been considered as convenient to carry out an anti-stigma program with the main objective of evaluating the impact of an intervention based on the education and promotion of mental health, aimed at teachers and counsellors of a secondary school. The specific objectives were to get to know which were the most stigmatising attitudes that prevailed in the sample before and after the intervention; to evaluate the knowledge of the teaching staff and counsellors on psychosis before the intervention; to analyse correlations between clinically relevant variables; and assess whether this programme was beneficial and feasible for alphabetising counsellors/teachers of educational centres on stigma and FEP.

METHODS

This was a non-randomised clinical trial in which a nursing intervention was performed.

TOOLS

a psychosis test (pre), Stigma Attribution Questionnaire (AQ-27) (pre-post), and satisfaction survey (post) were used. The inferential analysis included the Wilcoxon and the Pearson Correlation Test.

RESULTS

In the sample (n = 22), the predominant stigmatising attitude was "Help". The p-values obtained in the Wilcoxon Test were statistically significant, except for "Responsibility" and "Pity". The following constructs of interest were faced: "Fear"-"Age" and "Professional experience"; and "Help"-"Psychosis test".

CONCLUSIONS

Despite the scores obtained in "Responsibility" and "Pity", the intervention was useful for reducing stigma in the sample. Implications for the profession: There are adolescents who have suffered stigma from their teachers, and consequently have minimized their symptoms and not asked for help. For this reason, we implemented a nursing intervention based on the education and promotion of mental health, with the aim of expanding knowledge and reducing stigma. In fact, this intervention, which we carried out on high school teachers, managed to reduce the majority of stigmatizing attitudes measured on the stigma attribution scale.

BDNF gene Val66Met polymorphisms as a predictor for clinical presentation in schizophrenia - recent findings

Schizophrenia is a highly heritable, severe psychiatric disorder that involves dysfunctions in thinking, emotions, and behavior, with a profound impact on a person's ability to function normally in their daily life. Research efforts continue to focus on elucidating possible genetic underlying mechanisms of the disorder. Although the genetic loci identified to date to be significantly associated with schizophrenia risk do not represent disease-causing factors, each one of them could be seen as a possible incremental contributor. Considering the importance of finding new and more efficient pharmacological approaches to target the complex symptomatology of this disorder, in this scoping review, we are focusing on the most recent findings in studies aiming to elucidate the contribution of one of the genetic factors involved - the BDNF gene Val66Met polymorphisms. Here we performed a systematic search in Pubmed, Embase, and Web of Science databases with the search terms: (BDNF gene polymorphism) AND (schizophrenia) for articles published in the last 5 years. To be selected for this review, articles had to report on studies where genotyping for the BDNF Val66Met polymorphism was performed in participants diagnosed with schizophrenia (or schizophrenia spectrum disorders or first-episode psychosis). The search provided 35 results from Pubmed, 134 results from Embase, and 118 results from the Web of Science database. Twenty-two articles were selected to be included in this review, all reporting on studies where an implication of the BDNF Val66Met polymorphisms in the disorder's pathophysiology was sought to be elucidated. These studies looked at BDNF gene Val66Met polymorphism variants, their interactions with other genes of interest, and different facets of the illness. The Met/Met genotype was found to be associated with higher PANSS positive scores. Furthermore, Met/Met homozygous individuals appear to present with worse cognitive function and lower levels of serum BDNF. In the Val/Val genotype carriers, increased BDNF levels were found to correlate with weight gain under Risperidone treatment. However, due to heterogeneous results, the diversity in study populations and studies' small sample sizes, generalizations cannot be made. Our findings emphasize the need for further research dedicated to clarifying the role of gene polymorphisms in antipsychotic treatment to enhance specificity and efficacy in the treatment of schizophrenia.

Precision medicine in complex diseases-Molecular subgrouping for improved prediction and treatment stratification

Complex diseases are caused by a combination of genetic, lifestyle, and environmental factors and comprise common noncommunicable diseases, including allergies, cardiovascular disease, and psychiatric and metabolic disorders. More than 25% of Europeans suffer from a complex disease, and together these diseases account for 70% of all deaths. The use of genomic, molecular, or imaging data to develop accurate diagnostic tools for treatment recommendations and preventive strategies, and for disease prognosis and prediction, is an important step toward precision medicine. However, for complex diseases, precision medicine is associated with several challenges. There is a significant heterogeneity between patients of a specific disease-both with regards to symptoms and underlying causal mechanisms-and the number of underlying genetic and nongenetic risk factors is often high. Here, we summarize precision medicine approaches for complex diseases and highlight the current breakthroughs as well as the challenges. We conclude that genomic-based precision medicine has been used mainly for patients with highly penetrant monogenic disease forms, such as cardiomyopathies. However, for most complex diseases-including psychiatric disorders and allergies-available polygenic risk scores are more probabilistic than deterministic and have not yet been validated for clinical utility. However, subclassifying patients of a specific disease into discrete homogenous subtypes based on molecular or phenotypic data is a promising strategy for improving diagnosis, prediction, treatment, prevention, and prognosis. The availability of high-throughput molecular technologies, together with large collections of health data and novel data-driven approaches, offers promise toward improved individual health through precision medicine.

Reduced magnetic mismatch negativity: a shared deficit in psychosis and related risk

BACKGROUND

Abnormal auditory processing of deviant stimuli, as reflected by mismatch negativity (MMN), is often reported in schizophrenia (SCZ). At present, it is still under debate whether this dysfunctional response is specific to the full-blown SCZ diagnosis or rather a marker of psychosis in general. The present study tested MMN in patients with SCZ, bipolar disorder (BD), first episode of psychosis (FEP), and in people at clinical high risk for psychosis (CHR).

METHODS

Source-based MEG activity evoked during a passive auditory oddball task was recorded from 135 patients grouped according to diagnosis (SCZ, BD, FEP, and CHR) and 135 healthy controls also divided into four subgroups, age- and gender-matched with diagnostic subgroups. The magnetic MMN (mMMN) was analyzed as event-related field (ERF), Theta power, and Theta inter-trial phase coherence (ITPC).

RESULTS

The clinical group as a whole showed reduced mMMN ERF amplitude, Theta power, and Theta ITPC, without any statistically significant interaction between diagnosis and mMMN reductions. The mMMN subgroup contrasts showed lower ERF amplitude in all the diagnostic subgroups. In the analysis of Theta frequency, SCZ showed significant power and ITPC reductions, while only indications of diminished ITPC were observed in CHR, but no significant decreases characterized BD and FEP.

CONCLUSIONS

Significant mMMN alterations in people experiencing psychosis, also for diagnoses other than SCZ, suggest that this neurophysiological response may be a feature shared across psychotic disorders. Additionally, reduced Theta ITPC may be associated with risk for psychosis.

G protein-coupled estrogen receptor 1 deficiency impairs adult hippocampal neurogenesis in mice with schizophrenia

OBJECTIVE

This study aimed to confirm that G protein-coupled estrogen receptor 1 (GPER1) deficiency affects cognitive function by reducing hippocampal neurogenesis via the PKA/ERK/IGF-I signaling pathway in mice with schizophrenia (SZ).

METHODS

Mice were divided into four groups, namely, KO Con, WT Con, KO Con, and WT SZ (n = 12 in each group). All mice were accustomed to the behavioral equipment overnight in the testing service room. The experimental conditions were consistent with those in the animal house. Forced swimming test and Y-maze test were conducted. Neuronal differentiation and maturation were detected using immunofluorescence and confocal imaging. The protein in the PKA/ERK/IGF-I signaling pathway was tested using Western blot analysis.

RESULTS

GPER1 KO aggravated depression during forced swimming test and decreased cognitive ability during Y-maze test in the mouse model of dizocilpine maleate (MK-801)-induced SZ. Immunofluorescence and confocal imaging results demonstrated that GPER1 knockout reduced adult hippocampal dentate gyrus neurogenesis. Furthermore, GPER1-KO aggravated the hippocampal damage induced by MK-801 in mice through the PKA/ERK/IGF-I signaling pathway.

CONCLUSIONS

GPER1 deficiency reduced adult hippocampal neurogenesis and neuron survival by regulating the PKA/ERK/IGF-I signaling pathway in the MK-801-induced mouse model of SZ.

Dissociation between neuroanatomical and symptomatic subtypes in schizophrenia

BACKGROUND

Schizophrenia is a complex and heterogeneous syndrome with high clinical and biological stratification. Identifying distinctive subtypes can improve diagnostic accuracy and help precise therapy. A key challenge for schizophrenia subtyping is understanding the subtype-specific biological underpinnings of clinical heterogeneity. This study aimed to investigate if the machine learning (ML)-based neuroanatomical and symptomatic subtypes of schizophrenia are associated.

METHODS

A total of 314 schizophrenia patients and 257 healthy controls from four sites were recruited. Gray matter volume (GMV) and Positive and Negative Syndrome Scale (PANSS) scores were employed to recognize schizophrenia neuroanatomical and symptomatic subtypes using K-means and hierarchical methods, respectively.

RESULTS

Patients with ML-based neuroanatomical subtype-1 had focally increased GMV, and subtype-2 had widespread reduced GMV than the healthy controls based on either K-means or Hierarchical methods. In contrast, patients with symptomatic subtype-1 had severe PANSS scores than subtype-2. No differences in PANSS scores were shown between the two neuroanatomical subtypes; similarly, no GMV differences were found between the two symptomatic subtypes. Cohen's Kappa test further demonstrated an apparent dissociation between the ML-based neuroanatomical and symptomatic subtypes (P > 0.05). The dissociation patterns were validated in four independent sites with diverse disease progressions (chronic vs. first episodes) and ancestors (Chinese vs. Western).

CONCLUSIONS

These findings revealed a replicable dissociation between ML-based neuroanatomical and symptomatic subtypes of schizophrenia, which provides a new viewpoint toward understanding the heterogeneity of schizophrenia.

Immunoinflammatory and oxidative alterations in subjects with schizophrenia under clozapine: A meta-analysis

Clozapine presents immunoregulatory properties not well understood. To address this issue, we performed this systematic review to evaluate the immune alterations induced by clozapine and its relationship with the drug's clinical response and compare it with other antipsychotics. Our systematic review has selected nineteen studies meeting the inclusion criteria, from which eleven were included in the meta-analysis, totalizing 689 subjects distributed over three different comparisons. The results revealed that clozapine treatment activates the compensatory immune-regulatory system (CIRS) (Hedges's g = +1.049; CI +0.62 - +1.47, p < 0.001) but has no effects on the immune-Inflammatory Response System (IRS) (Hedges's g= -0.27; CI -1.76 - +1.22, p = 0.71), M1 macrophage (Hedges's g= -0.32; CI -1.78 - +1.14, p = 0.65) and Th1 (Hedge's g = 0.86; CI -0.93 - +1.814, p = 0.07) profiles. Comparing clozapine-treated patients with other anti-psychotics-treated, plasma levels of interleukin (IL)-6 were greater in the clozapine group (Hedge's g = 0.75; CI 0.35 - 1.15, p<0.001). In addition, higher IL-6 plasma levels after four weeks of clozapine treatment were related to the development of clozapine-induced fever; however, IL-6 levels recovered to baseline in 6-10 weeks due to an unexplained compensatory mechanism. In conclusion, our results show that clozapine treatment causes a time-dependent mixed immune profile characterized by increased IL-6 levels and CIRS activation, which may contribute to this drug mechanism of action and adverse effects. Future studies must be designed to investigate the relationship between clozapine-induced immune alterations and symptom remission, treatment resistance, and adverse effects, given the importance of this drug for treating resistant schizophrenia.

Review of Major Social Determinants of Health in Schizophrenia-Spectrum Psychotic Disorders: III. Biology

BACKGROUND

Social determinants of health (SDoHs) are nonmedical factors that significantly impact health and longevity. We found no published reviews on the biology of SDoHs in schizophrenia-spectrum psychotic disorders (SSPD).

STUDY DESIGN

We present an overview of pathophysiological mechanisms and neurobiological processes plausibly involved in the effects of major SDoHs on clinical outcomes in SSPD.

STUDY RESULTS

This review of the biology of SDoHs focuses on early-life adversities, poverty, social disconnection, discrimination including racism, migration, disadvantaged neighborhoods, and food insecurity. These factors interact with psychological and biological factors to increase the risk and worsen the course and prognosis of schizophrenia. Published studies on the topic are limited by cross-sectional design, variable clinical and biomarker assessments, heterogeneous methods, and a lack of control for confounding variables. Drawing on preclinical and clinical studies, we propose a biological framework to consider the likely pathogenesis. Putative systemic pathophysiological processes include epigenetics, allostatic load, accelerated aging with inflammation (inflammaging), and the microbiome. These processes affect neural structures, brain function, neurochemistry, and neuroplasticity, impacting the development of psychosis, quality of life, cognitive impairment, physical comorbidities, and premature mortality. Our model provides a framework for research that could lead to developing specific strategies for prevention and treatment of the risk factors and biological processes, thereby improving the quality of life and increasing the longevity of people with SSPD.

CONCLUSIONS

Biology of SDoHs in SSPD is an exciting area of research that points to innovative multidisciplinary team science for improving the course and prognosis of these serious psychiatric disorders.

Enhancing educational and vocational recovery in adolescents and young adults with early psychosis through Supported Employment and Education (SEEearly): study protocol for a multicenter randomized controlled trial

BACKGROUND

Psychotic disorders often develop a chronic course with devastating consequences for individuals, families, and societies. Early intervention programs for people in the first 5 years after the initial psychotic episode (early psychosis) can significantly improve the outcome and are therefore strongly recommended in national and international guidelines. However, most early intervention programs still focus on improving symptoms and relapse prevention, rather than targeting educational and vocational recovery. The aim of the present study is to explore the effects of Supported Employment and Education (SEE) following the Individual Placement and Support (IPS) model in people with early psychosis.

METHODS

The SEEearly trial compares treatment as usual (TAU) plus SEE to TAU alone in outpatient psychiatric settings. The study is a six-site, two-arm, single-blinded, superiority randomized controlled trial (RCT). Participants are randomly assigned (1:1) to the intervention or control group. Aiming to recruit 184 participants, with an assumed drop-out rate of 22%, we will be able to detect a 24% difference in the main outcome of employment/education with 90% power. We make assessments at baseline and at 6- and 12-month follow-ups. Outcome data on employment/education, medication, and current psychiatric treatment is obtained monthly through phone based short assessments. The primary outcome is steady participation for at least 50% of the 12-month follow-up in competitive employment and/or mainstream education. Secondary employment outcomes capture length of employment/education, time to first employment/education, monthly wages/educational attainment, and social return on investment (SROI). Secondary non-employment outcomes include subjective quality of life, psychopathology, substance use, relapse, hospitalization, and functional impairment. To be eligible, participants must be between 16 and 35 years, fulfill diagnostic criteria for early psychosis, and be interested in competitive employment and/or mainstream education.

DISCUSSION

In SEEearly, we hypothesize that participants with psychosis, who receive TAU plus SEE, present with better primary and secondary outcomes than participants, who receive TAU alone. Positive results of this study will justify SEE as an evidence-based strategy for clinical routine treatment in people with early psychosis.

TRIAL REGISTRATION

SEEearly was registered nationally and internationally in the German Clinical Trials Register (DRKS; identifier: DRKS00029660) on October 14, 2022.

Identifying risk factors for predominant negative symptoms from early stages in schizophrenia: A longitudinal and sex-specific study in first-episode schizophrenia patients

BACKGROUND

People with schizophrenia and predominant negative symptoms (PNS) present a different clinical and functional profile from those without such symptomatology. Few studies have examined the risk factors and the incidence of PNS in first-episode schizophrenia patients (FES) and differentiating by sex. This study aims to assess prevalence, demographic and clinical characteristics related to PNS from early stages and to study if there are sex-specific features in terms of developing PNS.

METHODS

In a sample of 121 FES patients derived from a multicentre and naturalistic study, those who developed PNS at 12-months were identified. Environmental, clinical, functional, and cognitive ratings were examined longitudinally. Binary logistic regressions were applied to detect baseline risk factors for developing PNS at one-year follow-up.

RESULTS

In the present FES cohort, 24.8% of the patients (n=30) developed PNS (20% of the women, 27.6% of the men). Compared to non-PNS (75.2%, n=91), at baseline, PNS group had more negative (t=-6.347; p<0.001) and depressive symptoms (t=-5.026; p<0.001), poorer premorbid adjustment (t=-2.791; p=0.006) and functional outcome (t=-2.649; p<0.001), more amotivation (t=-7.333; p<0.001), more expressivity alterations (t=-4.417; p<0.001), worse cognitive reserve (t=2.581; p<0.011), a lower estimated intelligent quotient (t=2.417; p=0.017), worse verbal memory (t=2.608; p=0.011), and worse fluency (t=2.614; p=0.010). Regressions showed that the premorbid adjustment was the main predictor of PNS in females (p=0.007; Exp(B)=1.106) while in males were a worse verbal memory performance (p=0.031; Exp(B)=0.989) and more alterations in the motivation domain (p=0.001; Exp(B)=1.607).

CONCLUSIONS

A different baseline clinical profile and notable risk factors differences in the development of PNS between males and females were found. Results suggest that sex may be an important confounder in studies comparing schizophrenia patients with predominant and non-predominant negative symptomatology.

Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

BACKGROUND

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder.

METHODS

The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status.

RESULTS

Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001).

CONCLUSIONS

Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent.

A tablet-based quantitative assessment of manual dexterity for detection of early psychosis

Background

We performed a pilot study on whether tablet-based measures of manual dexterity can provide behavioral markers for detection of first-episode psychosis (FEP), and whether cortical excitability/inhibition was altered in FEP.

Methods

Behavioral and neurophysiological testing was undertaken in persons diagnosed with FEP (N = 20), schizophrenia (SCZ, N = 20), autism spectrum disorder (ASD, N = 20), and in healthy control subjects (N = 20). Five tablet tasks assessed different motor and cognitive functions: Finger Recognition for effector (finger) selection and mental rotation, Rhythm Tapping for temporal control, Sequence Tapping for control/memorization of motor sequences, Multi Finger Tapping for finger individuation, and Line Tracking for visuomotor control. Discrimination of FEP (from other groups) based on tablet-based measures was compared to discrimination through clinical neurological soft signs (NSS). Cortical excitability/inhibition, and cerebellar brain inhibition were assessed with transcranial magnetic stimulation.

Results

Compared to controls, FEP patients showed slower reaction times and higher errors in Finger Recognition, and more variability in Rhythm Tapping. Variability in Rhythm Tapping showed highest specificity for the identification of FEP patients compared to all other groups (FEP vs. ASD/SCZ/Controls; 75% sensitivity, 90% specificity, AUC = 0.83) compared to clinical NSS (95% sensitivity, 22% specificity, AUC = 0.49). Random Forest analysis confirmed FEP discrimination vs. other groups based on dexterity variables (100% sensitivity, 85% specificity, balanced accuracy = 92%). The FEP group had reduced short-latency intra-cortical inhibition (but similar excitability) compared to controls, SCZ, and ASD. Cerebellar inhibition showed a non-significant tendency to be weaker in FEP.

Conclusion

FEP patients show a distinctive pattern of dexterity impairments and weaker cortical inhibition. Easy-to-use tablet-based measures of manual dexterity capture neurological deficits in FEP and are promising markers for detection of FEP in clinical practice.

Epigenetic regulation of metabotropic glutamate 2/3 receptors: Potential role for ultra-resistant schizophrenia?

Schizophrenia is a severe and debilitating psychiatric disorder characterized by early cognitive deficits, emotional and behavioral abnormalities resulted by a dysfunctional gene x environment interaction. Genetic and epigenetic abnormalities in cortical parvalbumin-positive GABAergic interneurons lead to alterations in glutamate-mediated excitatory neurotransmission, synaptic plasticity, and neuronal development. Epigenetic alterations during pregnancy or early phases of postnatal life are associated with schizophrenia vulnerability as well as inflammatory processes which are at the basis of brain pathology. An epigenetic animal model of schizophrenia showed specific changes in promoter DNA methylation activity of genes related to schizophrenia such as reelin, BDNF and GAD67, and altered expression and function of mGlu2/3 receptors in the frontal cortex. Although antipsychotic medications represent the main treatment for schizophrenia and generally show an optimal efficacy profile for positive symptoms and relatively poor efficacy for negative or cognitive symptoms, a considerable percentage of individuals show poor response, do not achieve a complete remission, and approximately 30 % of patients show treatment-resistance. Here, we explore the potential role of epigenetic abnormalities linked to metabotropic glutamate 2/3 receptors changes in expression and function as key molecular factors underlying the difference in response to antipsychotics.

The global burden of schizophrenia and the impact of urbanization during 1990-2019: An analysis of the global burden of disease study 2019

BACKGROUND AND HYPOTHESIS

The burden of schizophrenia is increasing. Assessing the global distribution of schizophrenia and understanding the association between urbanization factors and schizophrenia are crucial.

STUDY DESIGN

We conducted a two-stage analysis utilizing public data from GBD (global burden of disease) 2019 and the World Bank. First, the distribution of schizophrenia burden at the global, regional, and national levels as well as temporal trends was analyzed. Then, four composite indicators of urbanization (including demographic, spatial, economic, and eco-environment urbanization) were constructed from ten basic indicators. Panel data models were used to explore the relationship between urbanization indicators and the burden of schizophrenia.

RESULTS

In 2019, there were 23.6 million people with schizophrenia, an increase of 65.85% from 1990, and the country with the largest ASDR (age-standardized disability adjusted life years rate) was the United States of America, followed by Australia, and New Zealand. Globally, the ASDR of schizophrenia rose with the sociodemographic index (SDI). In addition, six basic urbanization indicators including urban population proportion, employment in industry/services proportion, urban population density, the population proportion in the largest city, GDP, and PM_2.5 concentration were positively associated with ASDR of schizophrenia, with the largest coefficients being urban population density. Overall, demographic, spatial, economic, and eco-environment urbanization all had positive effects on schizophrenia, and the estimated coefficients indicated that demographic urbanization was the most significant influence.

CONCLUSIONS

This study provided a comprehensive description of the global burden of schizophrenia and explored urbanization as a factor contributing to the variation in the burden of schizophrenia, and highlighted policy priorities for schizophrenia prevention in the context of urbanization.

The Patient Journey of Schizophrenia in Mental Health Services: Results from a Co-Designed Survey by Clinicians, Expert Patients and Caregivers

BACKGROUND

The Patient Journey Project aims to collect real-world experiences on schizophrenia management in clinical practice throughout all the phases of the disorder, highlighting virtuous paths, challenges and unmet needs.

METHODS

A 60-item survey was co-designed with all the stakeholders (clinicians, expert patients and caregivers) involved in the patient's journey, focusing on three areas: early detection and management, acute phase management and long-term management/continuity of care. For each statement, the respondents expressed their consensus on the importance and the degree of implementation in clinical practice. The respondents included heads of the Mental Health Services (MHSs) in the Lombardy region, Italy.

RESULTS

For early diagnosis and management, a strong consensus was found; however, the implementation degree was moderate-to-good. For acute phase management, a strong consensus and a good level of implementation were found. For long-term management/continuity of care, a strong consensus was found, but the implementation level was slightly above the cut-off, with 44.4% of the statements being rated as only moderately implemented. Overall, the survey showed a strong consensus and a good level of implementation.

CONCLUSIONS

The survey offered an updated evaluation of the priority intervention areas for MHSs and highlighted the current limitations. Particularly, early phases and chronicity management should be further implemented to improve the patient journey of schizophrenia patients.

Membrane Lipids in Ultra-High-Risk Patients: Potential Predictive Biomarkers of Conversion to Psychosis

Alterations in membrane lipids are reported in schizophrenia. However, no conclusion can be drawn regarding the extended and predictive value of these alterations in persons at ultra-high risk of psychosis (UHR). Recent studies suggested that sterols' impact on psychiatric disorders was underestimated. Here, we simultaneously explored sterols, fatty acids (FA), and phospholipids (PL) in UHR persons for the first time. We analysed erythrocyte membrane lipids in 61 UHR persons, including 29 who later converted to psychosis (UHR-C) and 32 who did not (UHC-NC). We used gas chromatography for FA and liquid chromatography tandem with mass spectrometry for sterols and phospholipids. Among UHR individuals, elevated baseline membrane linoleic acid level was associated with conversion to psychosis (26.1% vs. 60.5%, p = 0.02). Combining sterols, FA, and PL membrane composition improved the prediction of psychosis onset (AUC = 0.73). This is the first report showing that membrane sterol participates, with other membrane lipids, in modulating the risk of psychosis. It suggests that membrane lipids could be used as biomarkers for personalised medicine in UHR patients.

Thalamo-cortical circuits during sensory attenuation in emerging psychosis: a combined magnetoencephalography and dynamic causal modelling study

Evidence suggests that schizophrenia (ScZ) involves impairments in sensory attenuation. It is currently unclear, however, whether such deficits are present during early-stage psychosis as well as the underlying network and the potential as a biomarker. To address these questions, Magnetoencephalography (MEG) was used in combination with computational modeling to examine M100 responses that involved a "passive" condition during which tones were binaurally presented, while in an "active" condition participants were asked to generate a tone via a button press. MEG data were obtained from 109 clinical high-risk for psychosis (CHR-P) participants, 23 people with a first-episode psychosis (FEP), and 48 healthy controls (HC). M100 responses at sensor and source level in the left and right thalamus (THA), Heschl's gyrus (HES), superior temporal gyrus (STG) and right inferior parietal cortex (IPL) were examined and dynamic causal modeling (DCM) was performed. Furthermore, the relationship between sensory attenuation and persistence of attenuated psychotic symptoms (APS) and transition to psychosis was investigated in CHR-P participants. Sensory attenuation was impaired in left HES, left STG and left THA in FEP patients, while in the CHR-P group deficits were observed only in right HES. DCM results revealed that CHR-P participants showed reduced top-down modulation from the right IPL to the right HES. Importantly, deficits in sensory attenuation did not predict clinical outcomes in the CHR-P group. Our results show that early-stage psychosis involves impaired sensory attenuation in auditory and thalamic regions but may not predict clinical outcomes in CHR-P participants.

Schizophrenia Synaptic Pathology and Antipsychotic Treatment in the Framework of Oxidative and Mitochondrial Dysfunction: Translational Highlights for the Clinics and Treatment

Schizophrenia is a worldwide mental illness characterized by alterations at dopaminergic and glutamatergic synapses resulting in global dysconnectivity within and between brain networks. Impairments in inflammatory processes, mitochondrial functions, energy expenditure, and oxidative stress have been extensively associated with schizophrenia pathophysiology. Antipsychotics, the mainstay of schizophrenia pharmacological treatment and all sharing the common feature of dopamine D2 receptor occupancy, may affect antioxidant pathways as well as mitochondrial protein levels and gene expression. Here, we systematically reviewed the available evidence on antioxidants' mechanisms in antipsychotic action and the impact of first- and second-generation compounds on mitochondrial functions and oxidative stress. We further focused on clinical trials addressing the efficacy and tolerability of antioxidants as an augmentation strategy of antipsychotic treatment. EMBASE, Scopus, and Medline/PubMed databases were interrogated. The selection process was conducted in respect of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Several mitochondrial proteins involved in cell viability, energy metabolism, and regulation of oxidative systems were reported to be significantly modified by antipsychotic treatment with differences between first- and second-generation drugs. Finally, antioxidants may affect cognitive and psychotic symptoms in patients with schizophrenia, and although the evidence is only preliminary, the results indicate that further studies are warranted.

Dimensional model on how familial vulnerability and environmental factors impact transitional age youth psychopathology: The Transition_psy study

Background

Understanding psychopathology in transitional age youth (TAY) requires a complex model, incorporating familial vulnerability and environmental factors. A trans-diagnostic and dimensional approach seems the most appropriate. Transition_psy study aims to assess factors playing a role in TAY psychopathology and to define predictors.

Materials and methods

This article presents part of the Transition_psy study results, a case-control observational study. Youth aged 17 years old were recruited between June 2020 and December 2021, from both clinical [clinical population (CP) group] and non-clinical settings [non-clinical population (NCP) group]. Participants completed self-report questionnaires. The primary outcome to assess TAY psychopathology was the Youth-Self Report (YSR). We evaluated care needs with the Health of The Nation Outcome Scales For Children And Adolescents (HoNOSCA-SR) and quality of life with the World Health Organization Quality of Life - BREF (WHOQoL-BREF). Exposure factors included familial vulnerability, childhood, and present environmental factors, such as first-degree family history of psychopathology, the Childhood Trauma Questionnaire (CTQ) and the Family Assessment Device (FAD). YSR scores were compared, between groups, according to exposure factors with ANOVA and linear regression. We performed best subsets selection of multivariable analyses based on the Akaike Information Criterion. This study was registered with ClinicalTrials.gov (Identifier: NCT04333797).

Results

A total of 220 TAY (CP = 106, NCP = 114) were included in the study. Participants were aged 17 years old. The majority were female (69.1%), single (96.8%), and born in Belgium (82.3%). Clinical data were all significantly different between CP and NCP groups. YSR scores were found statistically different according to group (p < 0.001), first-degree family history of psychopathology (p < 0.001), CTQ (p < 0.001), and FAD (p < 0.001). Predictive dimensional model suggested that TAY psychopathology can be predicted by group, CTQ and FAD. Significant positive correlation was found between YSR and HoNOSCA (rho = 0.81) and negative correlation between YSR and physical and psychological health (rho = -0.69 and -0.71, respectively).

Conclusion

This study findings allowed to present a predictive dimensional model on TAY psychopathology, including belonging to a clinical population at transitional age, childhood trauma, and family dysfunction. Further research is needed to replicate Transition_psy study results in other samples. The proposed model could be used in clinical practice to improve assessment of TAY psychopathology.

Long Acting Ionically Paired Pamoate-based Suspension of Lurasidone: An exploration of Size Effects on in vitro Dissolution and in vivo Pharmacokinetic Behaviors

Latuda® is an oral tablet approved by the US Food and Drug Administration (FDA) for the treatment of schizophrenia. However, the clinical efficacy of Latuda® is compromised by patient noncompliance due to frequent daily administration, especially for patients experiencing severe schizophrenia, whose medication is often needed for several months to years. Hence, developing a long-acting injectable formulation of lurasidone is urgently needed. Herein, a poorly water-soluble lurasidone pamoate (LP) salt was synthesized via the facile ion pair-based salt formation technology. The solubility of LP was decreased by 233 folds compared with that of lurasidone hydrochloride (LH). Furthermore, suspensions of LH and LP with three different particle sizes, including 400 nm small-sized nanocrystals (SNCs), 4 μm medium-sized microcrystals (MMCs), and 15 μm large-sized microcrystals (LMCs) were prepared and characterized by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The in vitro release results showed that particle sizes had great effects on the sustained release of LH, where large-sized particles exhibited superior sustained release than the smaller ones. Besides, LP suspensions exhibited better sustained release than LH suspensions at the same size scale. Moreover, the pharmacokinetics showed that LP LMCs produced an extended in vivo intramuscularly injectable profile for up to 45 days, which was 10 days longer than that of the LH LMCs. Our findings demonstrated that particle size had appreciable impacts on drug sustained release and provided valuable knowledge for the rational design of optimized micronized suspensions for long-acting injectables.

The adenosine hypothesis of schizophrenia into its third decade: From neurochemical imbalance to early life etiological risks

The adenosine hypothesis of schizophrenia was conceptualized about two decades ago in an attempt to integrate two prominent theories of neurochemical imbalance that attribute the pathogenesis of schizophrenia to hyperfunction of the mesocorticolimbic dopamine neurotransmission and hypofunction of cortical glutamate neurotransmission. Given its unique position as an endogenous modulator of both dopamine and glutamate signaling in the brain, adenosine was postulated as a potential new drug target to achieve multiple antipsychotic actions. This new strategy may offer hope for improving treatment, especially in alleviating negative symptoms and cognitive deficits of schizophrenia that do not respond to current medications. To date, however, the adenosine hypothesis has yet led to any significant therapeutic breakthroughs. Here, we address two possible reasons for the impasse. First, neither the presence of adenosine functional deficiency in people with schizophrenia nor its causal relationship to symptom production has been satisfactorily examined. Second, the lack of novel adenosine-based drugs also impedes progress. This review updates the latest preclinical and clinical data pertinent to the construct validity of the adenosine hypothesis and explores novel molecular processes whereby dysregulation of adenosine signaling could be linked to the etiology of schizophrenia. It is intended to stimulate and revitalize research into the adenosine hypothesis towards the development of a new and improved generation of antipsychotic drugs that has eluded us for decades.

Adolescent raloxifene treatment in females prevents cognitive deficits in a neurodevelopmental rodent model of schizophrenia

The existence of sex differences in schizophrenia is a well documented phenomenon which led to the hypothesis that female sex hormones are neuroprotective and hence responsible for the more favorable disease characteristics seen in women. The current study sought to investigate the effects of estrogen-like agents administered during early adolescence on behavioral outcomes in adulthood using the neurodevelopmental maternal immune activation (MIA) rodent model of schizophrenia. Female MIA offspring were administered during the asymptomatic period of adolescence with either 17β-estradiol, raloxifene or saline and were tested in late adolescence and adulthood for schizophrenia-related behavioral performance. We report here that whereas adult female MIA offspring exhibited cognitive deficits in the form of retarded spatial learning, the administration of raloxifene during adolescence was sufficient in preventing these deficits and resulted in intact performance in the MIA group.

Neurocognition and functioning in adolescents at clinical high risk for psychosis

BACKGROUND

Once psychosis has set in, it is difficult for patients to achieve full recovery. Prevention of psychosis and early intervention are promising for improving the outcomes of this disorder. In the last two decades, neurocognition has been studied as a biomarker for clinical-high risk for psychosis (CHR-P). However, neurocognitive functioning has been under-investigated in adolescents.

METHODS

We enrolled 116 adolescents from 12 to 17 years old (mean = 15.27, SD = 1.56; 76 females). This 3-year cohort study aimed to identify differences in neurocognitive and overall functioning in three groups of adolescent patients divided according to the semi-structured interview Comprehensive Assessment of At-Risk Mental States (CAARMS): adolescents with established psychosis, adolescents with CHR-P, and adolescents not meeting either criteria (non-CHR-P). To differentiate the profiles, clinicians administered cognitive evaluation and neuropsychological tasks. Moreover, they filled in scales to assess their global, social, and role functioning and a questionnaire to assess the severity of the disease.

RESULTS

We made a between-group comparison on neurocognitive measures and found that the CHR-P and the psychosis groups differed in processing speed (TMT-A; p = .002 in BVN categorial fluency (p = .018), and Rey-Osterrieth complex figure drawing from memory task (p = .014), with psychosis group showing worse performance. No differences emerged between non-CHR-P and CHR-P (p = .014) individuals. CHR-P had better functioning than the psychosis group but worse than the non-CHR-P one.

CONCLUSIONS

These results confirm that neurocognition can be a helpful biomarker in identifying specific subgroups of adolescents with emerging psychopathology and help clinicians develop stratified preventive approaches.

Early systemic inflammation induces neurodevelopmental disorders: results from ARTEMIS, a French multicenter study of juvenile rheumatisms and systemic autoimmune and auto-inflammatory disorders and meta-analysis

Prenatal immune-mediated events are known risk factors for neurodevelopmental disorders in the offspring (NDD). Although the brain continues to develop for years after birth and many postnatal factors alter the regular trajectory of neurodevelopment, little is known about the impact of postnatal immune factors. To fill this gap we set up ARTEMIS, a cohort of juvenile rheumatisms and systemic autoimmune and auto-inflammatory disorders (jRSAID), and assessed their neurodevelopment. We then complemented our results with a systematic review and meta-analysis. In ARTEMIS, we used unsupervised and supervised analysis to determine the influence of jRSAID age at onset (AO) and delay in introduction of disease-modifying therapy (DMT) on NDD (NCT04814862). For the meta-analysis, we searched MEDLINE, EMBASE, PsycINFO, Cochrane, and Web of Science up to April 2022 without any restrictions on language, or article type for studies investigating the co-occurence of jRSAID and NDD (PROSPERO- CRD42020150346). 195 patients were included in ARTEMIS. Classification tree isolated 3 groups of patients (i) A low-risk group (AO > 130 months (m)) with 5% of NDD (ii) A medium-risk group (AO < 130 m and DMT < 2 m) with 20% of NDD (iii) and a high-risk-group (AO < 130 m and DMT > 2 m) with almost half of NDD. For the meta-analysis, 18 studies encompassing a total of (i) 46,267 children with jRSAID; 213,930 children with NDD, and 6,213,778 children as controls were included. We found a positive association between jRSAID and NDD with an OR = 1.44 [95% CI 1.31; 1.57] p < 0.0001, [I² = 66%, Tau² = 0.0067, p < 0.01]. Several sensitivity analyses were performed without changing the results. Metaregression confirmed the importance of AO (p = 0.005). Our study supports the association between jRSAID and NDD. AO and DMT have pivotal roles in the risk of developing NDD. We plead for systematic screening of NDD in jRSAID to prevent the functional impact of NDD.

The Inflammatory Signals Associated with Psychosis: Impact of Comorbid Drug Abuse

Psychosis and substance use disorders are two diagnostic categories whose association has been studied for decades. In addition, both psychosis spectrum disorders and drug abuse have recently been linked to multiple pro-inflammatory changes in the central nervous system. We have carried out a narrative review of the literature through a holistic approach. We used PubMed as our search engine. We included in the review all relevant studies looking at pro-inflammatory changes in psychotic disorders and substance use disorders. We found that there are multiple studies that relate various pro-inflammatory lipids and proteins with psychosis and substance use disorders, with an overlap between the two. The main findings involve inflammatory mediators such as cytokines, chemokines, endocannabinoids, eicosanoids, lysophospholipds and/or bacterial products. Many of these findings are present in different phases of psychosis and in substance use disorders such as cannabis, cocaine, methamphetamines, alcohol and nicotine. Psychosis and substance use disorders may have a common origin in an abnormal neurodevelopment caused, among other factors, by a neuroinflammatory process. A possible convergent pathway is that which interrelates the transcriptional factors NFκB and PPARγ. This may have future clinical implications.

Early treatment with JNJ-46356479, a mGluR2 modulator, improves behavioral and neuropathological deficits in a postnatal ketamine mouse model of schizophrenia

Positive allosteric modulators of the metabotropic glutamate receptor 2 (mGluR2), such as JNJ-46356479 (JNJ), may mitigate the glutamate storm during the early stages of schizophrenia (SZ), which could be especially useful in the treatment of cognitive and negative symptoms. We evaluated the efficacy of early treatment with JNJ or clozapine (CLZ) in reversing behavioral and neuropathological deficits induced in a postnatal ketamine (KET) mouse model of SZ. Mice exposed to KET (30 mg/kg) on postnatal days (PND) 7, 9, and 11 received JNJ or CLZ (10 mg/kg) daily in the adolescent period (PND 35-60). Mice exposed to KET did not show the expected preference for a novel object or for social novelty, but they recovered this preference with JNJ treatment. Similarly, KET group did not show the expected dishabituation in the fifth trial, but mice treated with JNJ or CLZ recovered an interest in the novel animal. Neuronal immunoreactivity also differed between treatment groups with mice exposed to KET showing a reduction in parvalbumin positive cells in the prefrontal cortex and decreased c-Fos expression in the hippocampus, which was normalized with the pharmacological treatment. JNJ-46356479 treatment in early stages may help improve the cognitive and negative symptoms, as well as certain neuropathological deficits, and may even obtain a better response than CLZ treatment. This may have relevant clinical translational applications since early treatment with mGluR2 modulators that inhibit glutamate release at the onset of critical phases of SZ may prevent or slow down the clinical deterioration of the disease.

Schizophrenia among young people first admitted to psychiatric inpatient care during early and middle adolescence

OBJECTIVE

This study explored the incidence and stability of schizophrenia in a large national register data of all adolescents first admitted to psychiatric inpatient care at ages 13-17 in Finland 1980-2010.

METHODS

The study population (N 17,112) comprised all Finnish citizens aged 13-17 receiving their first ever psychiatric inpatient treatment between 1980 and 2010 in Finland. To explore incidence and stability of schizophrenia, the diagnostic information on inpatient care or disability pension was obtained from the appropriate registers.

RESULTS

The incidence of schizophrenia disorders (F20 + F25) during adolescence was higher in the study population for those admitted to psychiatric inpatient care 1980-1989 than in other decades examined. Overall, psychiatric inpatient care during adolescence was a risk factor for subsequent schizophrenia, especially if a diagnosis of F20-29 was set although a considerable share of those with psychotic disorders other than schizophrenia diagnosis did not subsequently convert to schizophrenia. The stability of adolescent onset schizophrenia diagnosis was high.

CONCLUSION

Adolescents requiring psychiatric inpatient care have a higher later rate of schizophrenia diagnosis than prevalence at community level. Whereas adolescent onset schizophrenia diagnosis is a fairly stable diagnosis, there are other adolescent psychotic disorders which are more transient in nature.

Neurotoxic/Neuroprotective Effects of Clozapine and the Positive Allosteric Modulator of mGluR2 JNJ-46356479 in Human Neuroblastoma Cell Cultures

Current antipsychotics (APs) effectively control positive psychotic symptoms, mainly by blocking dopamine (DA) D2 receptors, but have little effect on negative and cognitive symptoms. Increased glutamate (GLU) release would trigger neurotoxicity, leading to apoptosis and synaptic pruning, which is involved in the pathophysiology of schizophrenia. New pharmacological strategies are being developed such as positive allosteric modulators (PAMs) of the metabotropic GLU receptor 2 (mGluR2) that inhibit the presynaptic release of GLU. We previously reported that treatment of adult mice with JNJ-46356479 (JNJ), a recently developed mGluR2 PAM, partially improved neuropathological deficits and schizophrenia-like behavior in a postnatal ketamine mouse model. In the present study, we evaluated, for the first time, the putative neuroprotective and antiapoptotic activity of JNJ in a human neuroblastoma cell line and compared it with the effect of clozapine (CLZ) as a clinical AP with the highest efficacy and with apparent utility in managing negative symptoms. Specifically, we measured changes in cell viability, caspase 3 activity and apoptosis, as well as in the expression of key genes involved in survival and cell death, produced by CLZ and JNJ alone and in combination with a high DA or GLU concentration as apoptosis inducers. Our results suggest that JNJ is not neurotoxic and attenuates apoptosis, particularly by decreasing the caspase 3 activation induced by DA and GLU, as well as increasing and decreasing the number of viable and apoptotic cells, respectively, only when cultures were exposed to GLU. Its effects seem to be less neurotoxic and more neuroprotective than those observed with CLZ. Moreover, JNJ partially normalized altered expression levels of glycolytic genes, which could act as a protective factor and be related to its putative neuroprotective effect. More studies are needed to define the mechanisms of action of this GLU modulator and its potential to become a novel therapeutic agent for schizophrenia.

Risk Factors for Psychotic Relapse After Dose Reduction or Discontinuation of Antipsychotics in Patients With Chronic Schizophrenia. A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND HYPOTHESIS

Although maintenance treatment with antipsychotics protects against psychotic relapse, high doses may hamper recovery. Therefore, dose reduction or discontinuation may be considered in patients with chronic schizophrenia. Here, we identified risk factors for psychotic relapse when doses are reduced.

STUDY DESIGN

We systematically searched MEDLINE, EMBASE, and PsycINFO from January 1950 through January 2021 and reviewed randomized controlled trials (RCTs) that reported relapse rates after antipsychotic dose reduction or discontinuation in patients with chronic schizophrenia. We calculated relative risks (RRs) with 95% confidence intervals (CIs) per person-year and sought to identify potential risk factors for relapse. The study is registered with PROSPERO (CRD42017058296).

STUDY RESULTS

Forty-seven RCTs (54 patient cohorts, 1746 person-years) were included. The RR for psychotic relapse with dose reduction/discontinuation versus maintenance treatment was 2.3 per person-year (95% CI: 1.9 to 2.8). The RR was higher with antipsychotic discontinuation, dose reduction to less than 3-5 mg haloperidol equivalent (HE), or relatively rapid dose reduction (<10 weeks). The RR was lower with long-acting injectable agents versus oral antipsychotic dose reduction. Other factors that increased the risk of psychotic relapse were younger age and short follow-up time.

CONCLUSIONS

Clinicians should take several risk factors for psychotic relapse into account when considering dose reduction in patients with chronic schizophrenia. Studies of a relatively fast reduction in antipsychotic dose support a minimum dose of 3-5 mg HE. However, if the dose is tapered more gradually, relapses related to medication withdrawal might be avoided, possibly enabling lower-end doses to be achieved.

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.