Matrix metalloproteinase 9 (MMP-9) activity, hippocampal extracellular free water, and cognitive deficits are associated with each other in early phase psychosis.

Increasing evidence points toward the role of the extracellular matrix, specifically matrix metalloproteinase 9 (MMP-9), in the pathophysiology of psychosis. MMP-9 is a critical regulator of the crosstalk between peripheral and central inflammation, extracellular matrix remodeling, hippocampal development, synaptic pruning, and neuroplasticity. Here, we aim to characterize the relationship between plasma MMP-9 activity, hippocampal microstructure, and cognition in healthy individuals and individuals with early phase psychosis. We collected clinical, blood, and structural and diffusion-weighted magnetic resonance imaging data from 39 individuals with early phase psychosis and 44 age and sex-matched healthy individuals. We measured MMP-9 plasma activity, hippocampal extracellular free water (FW) levels, and hippocampal volumes. We used regression analyses to compare MMP-9 activity, hippocampal FW, and volumes between groups. We then examined associations between MMP-9 activity, FW levels, hippocampal volumes, and cognitive performance assessed with the MATRICS battery. All analyses were controlled for age, sex, body mass index, cigarette smoking, and years of education. Individuals with early phase psychosis demonstrated higher MMP-9 activity (p < 0.0002), higher left (p < 0.05) and right (p < 0.05) hippocampal FW levels, and lower left (p < 0.05) and right (p < 0.05) hippocampal volume than healthy individuals. MMP-9 activity correlated positively with hippocampal FW levels (all participants and individuals with early phase psychosis) and negatively with hippocampal volumes (all participants and healthy individuals). Higher MMP-9 activity and higher hippocampal FW levels were associated with slower processing speed and worse working memory performance in all participants. Our findings show an association between MMP-9 activity and hippocampal microstructural alterations in psychosis and an association between MMP-9 activity and cognitive performance. Further, more extensive longitudinal studies should examine the therapeutic potential of MMP-9 modulators in psychosis.

Characterization of early psychosis patients carrying a genetic vulnerability to redox dysregulation: a computational analysis of mechanism-based gene expression profile in fibroblasts.

In view of its heterogeneity, schizophrenia needs new diagnostic tools based on mechanistic biomarkers that would allow early detection. Complex interaction between genetic and environmental risk factors may lead to NMDAR hypofunction, inflammation and redox dysregulation, all converging on oxidative stress. Using computational analysis, the expression of 76 genes linked to these systems, known to be abnormally regulated in schizophrenia, was studied in skin-fibroblasts from early psychosis patients and age-matched controls (N = 30), under additional pro-oxidant challenge to mimic environmental stress. To evaluate the contribution of a genetic risk related to redox dysregulation, we investigated the GAG trinucleotide polymorphism in the key glutathione (GSH) synthesizing enzyme, glutamate-cysteine-ligase-catalytic-subunit (gclc) gene, known to be associated with the disease. Patients and controls showed different gene expression profiles that were modulated by GAG-gclc genotypes in combination with oxidative challenge. In GAG-gclc low-risk genotype patients, a global gene expression dysregulation was observed, especially in the antioxidant system, potentially induced by other risks. Both controls and patients with GAG-gclc high-risk genotype (gclcGAG-HR) showed similar gene expression profiles. However, under oxidative challenge, a boosting of other antioxidant defense, including the master regulator Nrf2 and TRX systems was observed only in gclcGAG-HR controls, suggesting a protective compensation against the genetic GSH dysregulation. Moreover, RAGE (redox/inflammation interaction) and AGMAT (arginine pathway) were increased in the gclcGAG-HR patients, suggesting some additional risk factors interacting with this genotype. Finally, the use of a machine-learning approach allowed discriminating patients and controls with an accuracy up to 100%, paving the way towards early detection of schizophrenia.

[Psychiatry: what's new in 2022]. / Psychiatrie : ce qui a changé en 2022.

The period of study and/or vocational training coincides with the phase of life where a large proportion of psychiatric disorders emerge. It is therefore common to be asked by a young person in training to make adjustments to his or her training for psychological reasons. Some disorders that were thought to occur in childhood also exist in adults: this is the case of attention deficit disorder with or without hyperactivity, which must be detected and treated appropriately. The tools available for the treatment of psychiatric disorders are not limited to medication and the usefulness of psychotherapy or physical approaches, for example, is well known. We are less aware of the beneficial effects of exposure to nature and green spaces, which are however solidly supported by scientific studies - and which we should not underestimate.

La période des études et/ou de la formation professionnelle est une phase de vie au cours de laquelle émergent une grande partie des troubles psychiques. Il n'est donc pas rare d'être sollicité par un jeune en formation au sujet d'un aménagement de la formation pour des raisons psychiques. Certains des troubles qu'on pensait survenir dans l'enfance existent aussi chez l'adulte. C'est le cas du trouble de déficit de l'attention avec ou sans hyperactivité. Les outils à disposition pour le traitement des troubles psychiques ne se restreignent pas aux médicaments : on connaît l'utilité des psychothérapies ou des approches corporelles par exemple. On connaît moins les effets bénéfiques de l'exposition à la nature et aux espaces verts, qui sont pourtant solidement étayés par des études scientifiques et que l'on aurait tort de sous-estimer.

Multimodal Magnetic Resonance Imaging Depicts Widespread and Subregion Specific Anomalies in the Thalamus of Early-Psychosis and Chronic Schizophrenia Patients.

BACKGROUND AND HYPOTHESIS: Although the thalamus has a central role in schizophrenia pathophysiology, contributing to sensory, cognitive, and sleep alterations, the nature and dynamics of the alterations occurring within this structure remain largely elusive. Using a multimodal magnetic resonance imaging (MRI) approach, we examined whether anomalies: (1) differ across thalamic subregions/nuclei, (2) are already present in the early phase of psychosis (EP), and (3) worsen in chronic schizophrenia (SCHZ). STUDY DESIGN: T1-weighted and diffusion-weighted images were analyzed to estimate gray matter concentration (GMC) and microstructural parameters obtained from the spherical mean technique (intra-neurite volume fraction [VFINTRA)], intra-neurite diffusivity [DIFFINTRA], extra-neurite mean diffusivity [MDEXTRA], extra-neurite transversal diffusivity [TDEXTRA]) within 7 thalamic subregions. RESULTS: Compared to age-matched controls, the thalamus of EP patients displays previously unreported widespread microstructural alterations (VFINTRA decrease, TDEXTRA increase) that are associated with similar alterations in the whole brain white matter, suggesting altered integrity of white matter fiber tracts in the thalamus. In both patient groups, we also observed more localized and heterogenous changes (either GMC decrease, MDEXTRA increase, or DIFFINTRA decrease) in mediodorsal, posterior, and ventral anterior parts of the thalamus in both patient groups, suggesting that the nature of the alterations varies across subregions. GMC and DIFFINTRA in the whole thalamus correlate with global functioning, while DIFFINTRA in the subregion encompassing the medial pulvinar is significantly associated with negative symptoms in SCHZ. CONCLUSION: Our data reveals both widespread and more localized thalamic anomalies that are already present in the early phase of psychosis.

White Matter Alterations Between Brain Network Hubs Underlie Processing Speed Impairment in Patients With Schizophrenia.

Processing speed (PS) impairment is one of the most severe and common cognitive deficits in schizophrenia. Previous studies have reported correlations between PS and white matter diffusion properties, including fractional anisotropy (FA), in several fiber bundles in schizophrenia, suggesting that white matter alterations could underpin decreased PS. In schizophrenia, white matter alterations are most prevalent within inter-hub connections of the rich club. However, the spatial and topological characteristics of this association between PS and FA have not been investigated in patients. In this context, we tested whether structural connections comprising the rich club network would underlie PS impairment in 298 patients with schizophrenia or schizoaffective disorder and 190 healthy controls from the Australian Schizophrenia Research Bank. PS, measured using the digit symbol coding task, was largely (Cohen's d = 1.33) and significantly (P < .001) reduced in the patient group when compared with healthy controls. Significant associations between PS and FA were widespread in the patient group, involving all cerebral lobes. FA was not associated with other cognitive measures of phonological fluency and verbal working memory in patients, suggesting specificity to PS. A topological analysis revealed that despite being spatially widespread, associations between PS and FA were over-represented among connections forming the rich club network. These findings highlight the need to consider brain network topology when investigating high-order cognitive functions that may be spatially distributed among several brain regions. They also reinforce the evidence that brain hubs and their interconnections may be particularly vulnerable parts of the brain in schizophrenia.

Topology predicts long-term functional outcome in early psychosis.

Early intervention in psychosis is crucial to improving patient response to treatment and the functional deficits that critically affect their long-term quality of life. Stratification tools are needed to personalize functional deficit prevention strategies at an early stage. In the present study, we applied topological tools to analyze symptoms of early psychosis patients, and detected a clear stratification of the cohort into three groups. One of the groups had a significantly better psychosocial outcome than the others after a 3-year clinical follow-up. This group was characterized by a metabolic profile indicative of an activated antioxidant response, while that of the groups with poorer outcome was indicative of oxidative stress. We replicated in a second cohort the finding that the three distinct clinical profiles at baseline were associated with distinct outcomes at follow-up, thus validating the predictive value of this new stratification. This approach could assist in personalizing treatment strategies.

Rate and predictors of disengagement in an early psychosis program with time limited intensification of treatment.

BACKGROUND: Service disengagement is a frequent problem in early intervention in psychosis. The goal of this study was to evaluate the rate and variables associated with service disengagement in a three year specialized program that allows treatment intensification on a case to case basis. METHODS: 328 early psychosis patients were assessed at baseline on a large set of socio-demographic and clinical variables and were followed-up over 36 months. Patients who left the program for reasons related to engagement with care were compared to patients who completed the program. RESULTS: Rates of disengagement were low (6.3%). Patients with lower socio-economic status, who committed offences during the program or with a diagnosis of Schizophreniform/brief psychotic disorder were more likely to disengage from the program. CONCLUSIONS: The engagement strategies implemented in the context of our early intervention programs have allowed to keep disengagements to a relatively low level. In this context, only 3 variables emerged to guide adaptation of the intervention in order to improve this already good engagement rate.

Early onset of cannabis use and violent behavior in psychosis.

BACKGROUND: Although evidence from psychosis patients demonstrates the adverse effects of cannabis use (CU) at a young age and that the rate of CU is high in subgroups of young violent patients with psychotic disorders, little is known about the possible effect of the age of onset of CU on later violent behaviors (VB). So, we aimed to explore the impact of age at onset of CU on the risk of displaying VB in a cohort of early psychosis patients. METHOD: Data were collected prospectively over a 36-month period in the context of an early psychosis cohort study. A total of 265 patients, aged 18-35 years, were included in the study. Logistic regression was performed to assess the link between age of onset of substance use and VB. RESULTS: Among the 265 patients, 72 had displayed VB and 193 had not. While violent patients began using cannabis on average at age 15.29 (0.45), nonviolent patients had started on average at age 16.97 (0.35) (p = 0.004). Early-onset CU (up to age 15) was a risk factor for VB (odds ratio = 4.47, confidence interval [CI]: 1.13-20.06) when the model was adjusted for age group, other types of substance use, being a user or a nonuser and various violence risk factors and covariates. History of violence and early CU (until 15) were the two main risk factors for VB. CONCLUSIONS: Our results suggest that early-onset CU may play a role in the emergence of VB in early psychosis.

Stable biomarker identification for predicting schizophrenia in the human connectome.

Schizophrenia, as a psychiatric disorder, has recognized brain alterations both at the structural and at the functional magnetic resonance imaging level. The developing field of connectomics has attracted much attention as it allows researchers to take advantage of powerful tools of network analysis in order to study structural and functional connectivity abnormalities in schizophrenia. Many methods have been proposed to identify biomarkers in schizophrenia, focusing mainly on improving the classification performance or performing statistical comparisons between groups. However, the stability of biomarkers selection has been for long overlooked in the connectomics field. In this study, we follow a machine learning approach where the identification of biomarkers is addressed as a feature selection problem for a classification task. We perform a recursive feature elimination and support vector machines (RFE-SVM) approach to identify the most meaningful biomarkers from the structural, functional, and multi-modal connectomes of healthy controls and patients. Furthermore, the stability of the retrieved biomarkers is assessed across different subsamplings of the dataset, allowing us to identify the affected core of the pathology. Considering our technique altogether, it demonstrates a principled way to achieve both accurate and stable biomarkers while highlighting the importance of multi-modal approaches to brain pathology as they tend to reveal complementary information.

Correction: MMP9/RAGE pathway overactivation mediates redox dysregulation and neuroinflammation, leading to inhibitory/excitatory imbalance: a reverse translation study in schizophrenia patients.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Psychiatry: novelties in 2019]. / Psychiatrie.

Living in an urban environment increases the risk to develop psychosis. An interdisciplinary research project has allowed a better definition of urban stress components and the adaptation strategies applied by patients to face it. On this basis, the concept of « urban remediation ¼ has emerged as a strategy to help patients regain access to the city. Among the other new treatment approaches, we also discuss therapy through games, which, due to their flexibility and variety, can suit many different needs. These approaches allow the reinforcement of coping capacities through diverse strategies, ranging from the promotion of social interactions to cognitive restructuration or behavioral activation. In addition, the engaging nature of these games may facilitate access and adherence to treatment.

Vivre en milieu urbain augmente le risque de développer un trouble psychotique. Une recherche interdisciplinaire a permis d'identifier plus précisément les éléments qui composent le stress urbain et les stratégies des patients pour s'y adapter, et de développer la remédiation urbaine, stratégie thérapeutique visant à faciliter la reconquête de l'espace urbain. Les thérapies par le jeu, qui, du fait de leur flexibilité, peuvent quant à elles s'adapter à toutes sortes de besoins, et permettent de renforcer les stratégies d'adaptation des patients, en s'appuyant sur des stratégies de changements variées, allant du renforcement des interactions sociales à la restructuration cognitive ou à l'activation comportementale. De plus, l'attractivité des jeux pourrait faciliter l'entrée ou le maintien dans les soins.

Partial-volume modeling reveals reduced gray matter in specific thalamic nuclei early in the time course of psychosis and chronic schizophrenia.

The structural complexity of the thalamus, due to its mixed composition of gray and white matter, make it challenging to disjoint and quantify each tissue contribution to the thalamic anatomy. This work promotes the use of partial-volume-based over probabilistic-based tissue segmentation approaches to better capture thalamic gray matter differences between patients at different stages of psychosis (early and chronic) and healthy controls. The study was performed on a cohort of 23 patients with schizophrenia, 41 with early psychosis and 69 age and sex-matched healthy subjects. Six tissue segmentation approaches were employed to obtain the gray matter concentration/probability images. The statistical tests were applied at three different anatomical scales: whole thalamus, thalamic subregions and voxel-wise. The results suggest that the partial volume model estimation of gray matter is more sensitive to detect atrophies within the thalamus of patients with psychosis. However all the methods detected gray matter deficit in the pulvinar, particularly in early stages of psychosis. This study demonstrates also that the gray matter decrease varies nonlinearly with age and between nuclei. While a gray matter loss was found in the pulvinar of patients in both stages of psychosis, reduced gray matter in the mediodorsal was only observed in early psychosis subjects. Finally, our analyses point to alterations in a sub-region comprising the lateral posterior and ventral posterior nuclei. The obtained results reinforce the hypothesis that thalamic gray matter assessment is more reliable when the tissues segmentation method takes into account the partial volume effect.

Urbanicity: The need for new avenues to explore the link between urban living and psychosis.

AIM: A growing body of evidence suggests that urban living contributes to the development of psychosis. However, the mechanisms underlying this phenomenon remain unclear. This paper aims to explore the best available knowledge on the matter, identify research gaps and outline future prospects for research strategies. METHOD: A comprehensive literature survey on the main computerized medical research databases, with a time limit up to August 2017 on the issue of urbanicity and psychosis has been conducted. RESULTS: The impact of urbanicity may result from a wide range of factors (from urban material features to stressful impact of social life) leading to "urban stress." The latter may link urban upbringing to the development of psychosis through overlapping neuro- and socio-developmental pathways, possibly unified by dopaminergic hyperactivity in mesocorticolimbic system. However, "urban stress" is poorly defined and research based on patients' experience of the urban environment is scarce. CONCLUSIONS: Despite accumulated data, the majority of studies conducted so far failed to explain how specific factors of urban environment combine in patients' daily life to create protective or disruptive milieus. This undermines the translation of a vast epidemiological knowledge into effective therapeutic and urbanistic developments. New studies on urbanicity should therefore be more interdisciplinary, bridging knowledge from different disciplines (psychiatry, epidemiology, human geography, urbanism, etc.) in order to enrich research methods, ensure the development of effective treatment and preventive strategies as well as create urban environments that will contribute to mental well-being.

MMP9/RAGE pathway overactivation mediates redox dysregulation and neuroinflammation, leading to inhibitory/excitatory imbalance: a reverse translation study in schizophrenia patients.

Various mechanisms involved in schizophrenia pathophysiology, such as dopamine dysregulation, glutamate/NMDA receptor dysfunction, neuroinflammation or redox imbalance, all appear to converge towards an oxidative stress "hub" affecting parvalbumine interneurones (PVI) and their perineuronal nets (PNN) (Lancet Psychiatry. 2015;2:258-70); (Nat Rev Neurosci. 2016;17:125-34). We aim to investigate underlying mechanisms linking oxidative stress with neuroinflammatory and their long-lasting harmful consequences. In a transgenic mouse of redox dysregulation carrying a permanent deficit of glutathione synthesis (gclm-/-), the anterior cingulate cortex presented early in the development increased oxidative stress which was prevented by the antioxidant N-acetylcysteine (Eur J Neurosci. 2000;12:3721-8). This oxidative stress induced microglia activation and redox-sensitive matrix metalloproteinase 9 (MMP9) stimulation, leading to the receptor for advanced glycation end-products (RAGE) shedding into soluble and nuclear forms, and subsequently to nuclear factor-kB (NF-kB) activation and secretion of various cytokines. Blocking MMP9 activation prevented this sequence of alterations and rescued the normal maturation of PVI/PNN, even if performed after an additional insult that exacerbated the long term PVI/PNN impairments. MMP9 inhibition thus appears to be able to interrupt the vicious circle that maintains the long-lasting deleterious effects of the reciprocal interaction between oxidative stress and neuroinflammation, impacting on PVI/PNN integrity. Translation of these experimental findings to first episode patients revealed an increase in plasma soluble RAGE relative to healthy controls. This increase was associated with low prefrontal GABA levels, potentially predicting a central inhibitory/excitatory imbalance linked to RAGE shedding. This study paves the way for mechanistically related biomarkers needed for early intervention and MMP9/RAGE pathway modulation may lead to promising drug targets.

Moderating role of cannabis use between insight and depression in early psychosis.

BACKGROUND: A high level of insight in first episode psychosis (FEP) is positively correlated to important prognostic factors such as medication adherence and functional outcome but is associated with increased depression level and suicidal behavior. AIMS: This is the first study questioning the potential moderating role of cannabis use in the relationship between insight and depression one year after a FEP. METHOD: In this prospective observational study, we enrolled 214 FEP patients who had provided informed consent and been referred to a specialized early psychosis program and followed for 36 months. A series of multivariate regression models were used. Baseline insight, medication adherence and cannabis use (level of use on a continuum) were entered as independent variables, while the PANSS (positive and negative), the MADRS and the SOFAS scores after one year were alternately selected as the dependent variable. RESULTS: We found a three-way interaction term between cannabis use, insight and medication adherence on depression level one year after the entry into the program. A high level of insight was significantly associated with higher MADRS scores in patients with high cannabis use, while depression decreased in high-insight patients with low cannabis use. CONCLUSIONS: Cannabis use continuation during the year following a first episode psychosis may play a significant role in the development or the maintenance of post-psychotic depression in patients who present with high level of insight and adherence to medication, stressing the need for specific therapeutic strategies in this subgroup of patients.

Urban remediation: a new recovery-oriented strategy to manage urban stress after first-episode psychosis.

PURPOSE: Urban living is a major risk factor for psychosis. Considering worldwide increasing rates of urbanization, new approaches are needed to enhance patients' wellbeing in cities. Recent data suggest that once psychosis has emerged, patients struggle to adapt to urban milieu and that they lose access to city centers, which contributes to isolation and reduced social contacts. While it is acknowledged that there are promising initiatives to improve mental health in cities, concrete therapeutic strategies to help patients with psychosis to better handle urban stress are lacking. We believe that we should no longer wait to develop and test new therapeutic approaches. METHOD: In this review, we first focus on the role of urban planning, policies, and design, and second on possible novel therapeutic strategies at the individual level. We review how patients with psychosis may experience stress in the urban environment. We then review and describe a set of possible strategies, which could be proposed to patients with the first-episode psychosis. RESULTS: We propose to group these strategies under the umbrella term of 'urban remediation' and discuss how this novel approach could help patients to recover from their first psychotic episode. CONCLUSION: The concepts developed in this paper are speculative and a lot of work remains to be done before it can be usefully proposed to patients. However, considering the high prevalence of social withdrawal and its detrimental impact on the recovery process, we strongly believe that researchers should invest this new domain to help patients regain access to city centers.

N-Acetyl-Cysteine Supplementation Improves Functional Connectivity Within the Cingulate Cortex in Early Psychosis: A Pilot Study.

BACKGROUND: There is increasing evidence that redox dysregulation, which can lead to oxidative stress and eventually to impairment of oligodendrocytes and parvalbumin interneurons, may underlie brain connectivity alterations in schizophrenia. Accordingly, we previously reported that levels of brain antioxidant glutathione in the medial prefrontal cortex were positively correlated with increased functional connectivity along the cingulum bundle in healthy controls but not in early psychosis patients. In a recent randomized controlled trial, we observed that 6-month supplementation with a glutathione precursor, N-acetyl-cysteine, increased brain glutathione levels and improved symptomatic expression and processing speed. METHODS: We investigated the effect of N-acetyl-cysteine supplementation on the functional connectivity between regions of the cingulate cortex, which have been linked to positive symptoms and processing speed decline. In this pilot study, we compared structural connectivity and resting-state functional connectivity between early psychosis patients treated with 6-month N-acetyl-cysteine (n = 9) or placebo (n = 11) supplementation with sex- and age-matched healthy control subjects (n = 74). RESULTS: We observed that 6-month N-acetyl-cysteine supplementation increases functional connectivity along the cingulum and more precisely between the caudal anterior part and the isthmus of the cingulate cortex. These functional changes can be partially explained by an increase of centrality of these regions in the functional brain network. CONCLUSIONS: N-acetyl-cysteine supplementation has a positive effect on functional connectivity within the cingulate cortex in early psychosis patients. To our knowledge, this is the first study suggesting that increased brain glutathione levels via N-acetyl-cysteine supplementation may improve brain functional connectivity.

Migration in patients with early psychosis: A 3-year prospective follow-up study.

Early psychosis programs treat high ratios of migrants, given they display higher rates of psychosis. Studies on this topic are limited and less is known about outcomes. The aim of this study was to compare the premorbid, baseline and outcome profile of patients according to migration (M) and migration in psychosocial adversity (MA) in order to explore if there were differences suggesting particular needs in terms of treatment. 257 early psychosis patients aged 18-35 years old were followed-up over 36 months. MA (29.6%) and M (17.9%) were compared to patients who were born in Switzerland (NM). At entry to the program, MA patients had poorer functional levels and higher symptom intensity. MA patients were more likely to report past exposure to trauma. While M patients have similar outcome compared to NM patients, MA patients were less likely to reach symptom remission, displayed lower functioning and were more likely to relapse. Results suggests that migration in adversity is a potential determinant of functional impairment in early psychosis. While patients who migrated in other contexts have a better outcome, patients who experienced migration in adversity have specific needs considering they are less integrated and more likely to have been exposed to trauma.

Brain connectivity alterations in early psychosis: from clinical to neuroimaging staging.

Early in the course of psychosis, alterations in brain connectivity accompany the emergence of psychiatric symptoms and cognitive impairments, including processing speed. The clinical-staging model is a refined form of diagnosis that places the patient along a continuum of illness conditions, which allows stage-specific interventions with the potential of improving patient care and outcome. This cross-sectional study investigates brain connectivity features that characterize the clinical stages following a first psychotic episode. Structural brain networks were derived from diffusion-weighted MRI for 71 early-psychosis patients and 76 healthy controls. Patients were classified into stage II (first-episode), IIIa (incomplete remission), IIIb (one relapse), and IIIc (two or more relapses), according to the course of the illness until the time of scanning. Brain connectivity measures and diffusion parameters (fractional anisotropy, apparent diffusion coefficient) were investigated using general linear models and sparse linear discriminant analysis (sLDA), studying distinct subgroups of patients who were at specific stages of early psychosis. We found that brain connectivity impairments were more severe in clinical stages following the first-psychosis episode (stages IIIa, IIIb, IIIc) than in first-episode psychosis (stage II) patients. These alterations were spatially diffuse but converged on a set of vulnerable regions, whose inter-connectivity selectively correlated with processing speed in patients and controls. The sLDA suggested that relapsing-remitting (stages IIIb, IIIc) and non-remitting (stage IIIa) patients are characterized by distinct dysconnectivity profiles. Our results indicate that neuroimaging markers of brain dysconnectivity in early psychosis may reflect the heterogeneity of the illness and provide a connectomics signature of the clinical-staging model.

Frontal cortical thickness correlates positively with impulsivity in early psychosis male patients.

AIM: Impulsive behaviours, which are frequent in young people suffering from psychosis have been linked to risky and violent behaviours and participate to the burden of psychotic illness. Given that morphological brain correlates of impulsivity in schizophrenia have been poorly investigated especially in young adults, the aim of this study was to investigate the relationship between impulsivity and cortical thickness in early psychosis (EP) patients. METHOD: A total of 17 male subjects in the early phase of psychosis were recruited. Impulsivity was assessed with the Lecrubier Impulsivity Rating Scale. Mean cortical thickness was extracted from magnetic resonance imaging brain scans, using surface-based methods. RESULTS: Mean cortical thickness in the frontal lobe correlated positively with mean impulsivity in EP male patients. CONCLUSION: Our results suggest that psychotic subjects exhibiting higher impulsivity have larger frontal cortical thickness, which may pave the way towards the identification of patients with a higher risk to display impulsive behaviours.