M-O Krebs

M-O Krebs
Inserm 1266 - Groupe Hospitalier Universitaire Paris - Sainte Anne · Pôle HU Evaluation prévention innovation thérapeutique

MD, PhD

About

570
Publications
71,661
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14,512
Citations
Citations since 2017
162 Research Items
6147 Citations
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201720182019202020212022202302004006008001,0001,200

Publications

Publications (570)
Article
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IntroductionFolates, the main actors in one-carbon (C1) metabolism, are involved in synthesising monoamines and maintaining genomic stability. Previous studies support the association between C1 metabolism and schizophrenia. The main purpose of this study was to assess the prevalence of plasma folate, and/or vitamin B12 deficiencies and hyperhomocy...
Article
On June 2022, the 2nd Webinar "Neurodevelopmental Disorders (NDD) without boundaries took place at the Imagine Institute in Paris and was broadcasted live and in replay. The aim of this webinar is to address NDD in a dimensional rather than in a categorical approach. Several speakers were invited to present their researches on the subject. Classifi...
Article
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Background Adverse childhood experiences (ACE) can affect educational attainments, but little is known about their impact on educational achievements in people at clinical high risk of psychosis (CHR). Methods In total, 344 CHR individuals and 67 healthy controls (HC) were recruited as part of the European Community’s Seventh Framework Programme-f...
Article
Background: The Collaborative Outcome study on Health and Functioning during Infection Times (COH-FIT; www.coh-fit.com) is an anonymous and global online survey measuring health and functioning during COVID-19 pandemic. The aim of this study was to test concurrently the validity of COH-FIT items and the internal validity of the co-primary outcome,...
Article
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Background and hypothesis Around 20% of people at clinical high risk (CHR) for psychosis later develop a psychotic disorder, but it is difficult to predict who this will be. We assessed the incidence of hearing speech (termed speech illusions [SIs]) in noise in CHR participants and examined whether this was associated with adverse clinical outcomes...
Article
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Schizophrenia is highly heritable and aggregating in families, but genetics alone does not exclusively explain the pathogenesis. Many risk factors, including childhood trauma, viral infections, migration, and the use of cannabis, are associated with schizophrenia. Adolescence seems to be the critical period where symptoms of the disease manifest. T...
Article
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Introduction Health student’s mental health is considered a public health issue that dramatically increased with COVID 19’s pandemic. However, very few studies assessed the prevalence of mental health in medical, pharmacist, and dental students. Objectives Our goal was to assess mental health in health students from the same university one year af...
Article
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Background The mental health of health students is considered a public health issue which increased dramatically with the COVID 19’s pandemic. Few studies have assessed the prevalence of depression in medical, pharmacy, and dental students. Our goal was to assess mental health in health students from the same university and identify the associated...
Article
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Objective: People at ultra-high risk (UHR) for psychosis have a high prevalence of tobacco smoking, and rates are even higher among the subgroup that later develop a psychotic disorder. However, the longitudinal relationship between the course of tobacco smoking and clinical outcomes in UHR subjects is unknown. Methods: We investigated associati...
Article
Prior research suggests that certain psychiatric symptoms could be associated with increased risk of death. However, it remains unclear whether this association could rely on all or specific symptoms. In this report, we used data from a multicenter 5-year prospective study (N = 641) of older adults with an ICD-10 diagnosis of schizophrenia, bipolar...
Article
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Objective To examine the association between baseline alterations in grey matter volume (GMV) and clinical and functional outcomes in people at clinical high risk (CHR) for psychosis. Methods 265 CHR individuals and 92 healthy controls were recruited as part of a prospective multi-centre study. After a baseline assessment using magnetic resonance...
Article
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The long lapse between the presumptive origin of schizophrenia (SCZ) during early development and its diagnosis in late adolescence has hindered the study of crucial neurodevelopmental processes directly in living patients. Dopamine, a neurotransmitter consistently associated with the pathophysiology of SCZ, participates in several aspects of brain...
Article
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Brain anomalies are frequently found in early psychoses. Although they may remain undetected for many years, their interpretation is critical for differential diagnosis. In secondary psychoses, their identification may allow specific management. They may also shed light on various pathophysiological aspects of primary psychoses. Here we reviewed ca...
Article
Current treatments for trauma-related disorders remain ineffective for many patients.¹,² Fear extinction deficiency is a prominent feature of these diseases,³ and many behavioral treatments rely on extinction training.⁴,⁵ However, in many patients, therapy is followed by a relapse of symptoms, and the underpinnings of such interindividual variation...
Article
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Psychosis frequently occurs during adolescence and young adulthood, possibly as a result of gene-environment interactions, mediated by epigenetic mechanisms such as DNA methylation. Methylation patterns can be leveraged to predict epigenetic age in order to identify anomalies in aging trajectories that may be associated with the emergence of psycho...
Article
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Background We developed five tablet-based tasks (applications) to measure multiple components of manual dexterity. Aim: to test reliability and validity of tablet-based dexterity measures in healthy participants. Methods Tasks included: (1) Finger recognition to assess mental rotation capacity. The subject taps with the finger indicated on a virtu...
Article
Background: . High-quality comprehensive data on short-/long-term physical/mental health effects of the COVID-19 pandemic are needed. Methods: . The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT) is an international, multi-language (n=30) project involving >230 investigators from 49 countries/territories/re...
Article
Full-text available
Background: COVID-19 sanitary crisis is associated with emotional difficulties such as depression, anxiety and reactional post-traumatic symptoms among healthcare workers. Indeed, healthcare workers were particularly exposed to COVID-19 sanitary crisis. This study aimed to investigate the effects of exposure to COVID-19 sanitary crisis on affective...
Article
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The OTX2 homeoprotein transcription factor is expressed in the dopaminergic neurons of the ventral tegmental area, which projects to limbic structures controlling complex behaviors. OTX2 is also produced in choroid plexus epithelium, from which it is secreted into cerebrospinal fluid and transferred to limbic structure parvalbumin interneurons. Pre...
Preprint
Full-text available
The long lapse between the presumptive origin of schizophrenia (SCZ) during early development and its diagnosis in late adolescence has hindered the study of crucial neurodevelopmental processes directly in living patients. Dopamine, a neurotransmitter consistently associated with the pathophysiology of SCZ, participates in several aspects of brain...
Article
Full-text available
Cognitive impairment is a core feature of schizophrenia which precedes the onset of full psychotic symptoms, even in the ultra-high-risk stage (UHR). Polygenic risk scores (PRS) can be computed for many psychiatric disorders and phenotyping traits, including scores for resilience. We explored the correlations between several PRS and neurocognition...
Article
Background: The COVID-19 pandemic has altered daily routines and family functioning, led to closing schools, and dramatically limited social interactions worldwide. Measuring its impact on mental health of vulnerable children and adolescents is crucial. Methods: The Collaborative Outcomes study on Health and Functioning during Infection Times (C...
Article
Full-text available
Robust deficits in cognitive functioning are present in people with psychosis and are evident in the early stages of the disorder. Impairments in verbal memory and verbal fluency are reliably seen in individuals at clinical high-risk for psychosis (CHR) compared to healthy populations. As previous studies have shown a relationship between cognition...
Preprint
Full-text available
Current treatments for trauma-related disorders remain ineffective for many patients. Here, we modeled interindividual differences in post-therapy fear relapse with a novel ethologically relevant trauma recovery paradigm. After traumatic fear conditioning, rats underwent fear extinction while foraging in a large enriched arena, permitting the expre...
Article
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Background Suicide is a leading cause of death worldwide, and non-fatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genom...
Article
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Introduction Diagnoses of anxiety and/or depression are common in subjects at Ultra-High Risk for Psychosis (UHR) and associated with extensive functional impairment. Less is known about the impact of affective comorbidities on the prospective course of attenuated psychotic symptoms (APS). Method Latent class mixed modelling identified APS traject...
Article
Background: Schizophrenia-spectrum disorders (SSD) and Autism spectrum disorders (ASD) are neurodevelopmental disorders that share clinical, cognitive, and genetic characteristics, as well as particular white matter (WM) abnormalities. In this study, we aimed to investigate the role of a set of oligodendrocyte/myelin-related (OMR) genes and their...
Article
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Important questions remain about the profile of cognitive impairment in psychotic disorders across adulthood and illness stages. The age-associated profile of familial impairments also remains unclear, as well as the effect of factors, such as symptoms, functioning, and medication. Using cross-sectional data from the EU-GEI and GROUP studies, compr...
Article
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Background: Deficit in social communication is a core feature in Autism Spectrum Disorder but remains poorly assessed in classical clinical practice, especially in adult populations. This gap between needs and practice is partly due to a lack of standardized evaluation tools. The multicentric Research group in psychiatry GDR3557 (Institut de Psychi...
Article
Background: . High-quality comprehensive data on short-/long-term physical/mental health effects of the COVID�19 pandemic are needed. Methods: . The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT) is an international, multi-language (n=30) project involving >230 investigators from 49 countries/territories/r...
Article
Background: Primary prevention has the potential to modify the course of depression, but the consistency and magnitude of this effect are currently undetermined. Methods: PRISMA and RIGHT compliant (PROSPERO:CRD42020179659) systematic meta-review, PubMed/Web of Science, up to June 2020. Meta-analyses of controlled interventions for the primary prev...
Article
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Serum neuronal autoantibodies, such as those to the NMDA receptor (NMDAR), are detectable in a subgroup of patients with psychotic disorders. It is not known if they are present before the onset of psychosis or whether they are associated with particular clinical features or outcomes. In a case-control study, sera from 254 subjects at clinical high...
Article
Résumé Introduction La durée de psychose non traitée est un facteur important de mauvais pronostic, toutefois il manque des outils pour faciliter le repérage des situations à risque d’évolution vers la psychose. Nous présentons ici la validation d’une version française de l’auto-questionnaire 16-items Prodromal Questionnaire (fPQ16). Méthodes Ent...
Article
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Background Although clozapine is the most effective antipsychotic drug for treatment-resistant schizophrenia, it leads to a poor or partial response in 40 to 70% of patients. Augmentation of clozapine with electroconvulsive therapy (ECT) is a highly effective and relatively safe treatment for these clozapine-resistant patients. However, parameters...
Preprint
Full-text available
Suicide is a leading cause of death worldwide and non-fatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both are known to have a substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. We conducted a genome-wide...
Article
Full-text available
Objectives: The number of DNA methylome and RNA transcriptome studies is growing, but investigators have to consider the cell type composition of tissues used. In blood samples, the data reflect the picture of a mixture of different cells. Specialized algorithms can address the cell-type heterogeneity issue. We tested if these corrections are corr...
Article
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To improve the prediction of the individual risk of conversion to psychosis in UHR subjects, by considering all CAARMS’ symptoms at first presentation and using a multivariate machine learning method known as logistic regression with Elastic-net shrinkage. 46 young individuals who sought help from the specialized outpatient unit at Sainte-Anne hosp...
Article
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Background: Psychosis is associated with a reasoning bias, which manifests as a tendency to 'jump to conclusions'. We examined this bias in people at clinical high-risk for psychosis (CHR) and investigated its relationship with their clinical outcomes. Methods: In total, 303 CHR subjects and 57 healthy controls (HC) were included. Both groups we...
Article
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Background. Psychosis is associated with a reasoning bias, which manifests as a tendency to ‘jump to conclusions’. We examined this bias in people at clinical high-risk for psychosis (CHR) and investigated its relationship with their clinical outcomes. Methods. In total, 303 CHR subjects and 57 healthy controls (HC) were included. Both groups were...
Conference Paper
La moitié des maladies psychiatriques se manifeste avant l’âge de 14 ans, et les trois quarts avant 24 ans, suggérant que l’enfance, l’adolescence, et le début de l’âge adulte sont des fenêtres de grande fragilité aux troubles mentaux. La schizophrénie survient ainsi à l’adolescence tardive chez des individus à risque, repérables cliniquement, et d...
Article
Importance Biomarkers that are predictive of outcomes in individuals at risk of psychosis would facilitate individualized prognosis and stratification strategies. Objective To investigate whether proteomic biomarkers may aid prediction of transition to psychotic disorder in the clinical high-risk (CHR) state and adolescent psychotic experiences (P...
Article
Background Ocular-motor inhibition errors and saccadic hypometria occur at elevated rates in biological relatives of schizophrenic patients. The memory-guided saccade (MS) paradigm requires a subject to inhibit reflexive saccades (RSs) and to programme a delayed saccade towards a remembered target. Method MS, RS, and central fixation (CF) tasks wer...
Article
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Introduction: The emergence of psychosis in at-risk individuals results from interactions between genetic vulnerability and environmental factors, possibly involving dysregulation of the hypothalamic-pituitary-adrenal axis. Hypercorticism was indeed described in schizophrenia and ultra-high-risk states, but its association with clinical outcome ha...
Article
Schizophrenia is an illness characterized by positive symptoms, negative symptoms, and cognitive impairments. Cognitive impairments occur before the onset of psychosis and could reflect glutamatergic dysregulation. Thus, identifying associations between genetic variations in genes coding for glutamatergic receptors and cognitive impairment in schiz...
Article
Full-text available
Background A key clinical challenge in the management of individuals at clinical high risk for psychosis (CHR) is that it is difficult to predict their future clinical outcomes. Here, we investigated if the levels of circulating molecular lipids are related to adverse clinical outcomes in this group. Methods Serum lipidomic analysis was performed...
Article
Full-text available
Aberrant perceptional experiences are a potential early marker of psychosis development. Earlier studies have found experimentally assessed speech illusions to be associated with positive symptoms in patients with psychotic disorders, but findings for attenuated symptoms in individuals without psychotic disorders have been inconsistent. Also, the r...
Article
Background: Patients suffering from schizophrenic psychosis show reduced synaptic connectivity compared to healthy individuals. Furthermore, the use of cannabis often precedes the onset of schizophrenic psychosis. Therefore, we investigated whether consumption of cannabis has an impact on the methylation pattern of schizophrenia candidate genes co...
Article
Full-text available
The seven human 14-3-3 proteins are encoded by the YWHA-gene family. They are expressed in the brain where they play multiple roles including the modulation of synaptic plasticity and neuronal development. Previous studies have provided arguments for their involvement in schizophrenia, but their role during disease onset is unknown. We explored the...
Article
Résumé Les patients souffrant de trouble psychiatrique ont une espérance de vie réduite. Cette diminution est d’environ 15 ans dans la schizophrénie. De nombreux facteurs étiologiques ont été proposés : conséquences des symptômes psychiatriques, mauvaise alimentation, absence d’activité physique, tabagisme, effets secondaires du traitement antipsyc...
Article
Full-text available
Background Neural information processing is subject to noise and this leads to variability in neural firing and behavior. Schizophrenia has been associated with both more variable motor control and impaired cortical inhibition, which is crucial for excitatory/inhibitory balance in neural commands. Hypothesis In this study, we hypothesized that imp...
Article
Full-text available
Background Individuals at clinical high risk (CHR) of psychosis have an approximately 20% probability of developing psychosis within 2 years, as well as an associated risk of non-psychotic disorders and functional impairment. People with subclinical psychotic experiences (PEs) are also at risk of future psychotic and non-psychotic disorders and dec...
Article
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Background Genetic vulnerability to psychosis is polygenic, involving multiple genes with small individual effects (Psychiatric Genomics Consortium (PGC), 2014). The risk of psychosis is also related to environmental factors, such as childhood trauma (Lardinois et al, 2011). Although the onset of psychosis is thought to result from the interaction...
Article
Full-text available
Résumé Le développement cérébral est un phénomène complexe, qui s’étend de la vie fœtale à l’adolescence, pendant laquelle la maturation cérébrale suit une série d’événements ordonnés incluant des périodes critiques de plasticité. Le cerveau est particulièrement sensible à l’environnement pendant ces remaniements. Le système endocannabinoïde partic...
Article
RÉSUMÉ Objectifs: La pandémie de la maladie à coronavirus (COVID-19) a provoqué une crise sanitaire majeure et mis en quarantaine la moitié de la population planétaire. En France, elle a provoqué une réorganisation en urgence de l’offre de soins mobilisant les soignants dans un climat d’incertitude. L'objectif du présent article est de faire le poi...
Article
Importance Detection, prognosis, and indicated interventions in individuals at clinical high risk for psychosis (CHR-P) are key components of preventive psychiatry. Objective To provide a comprehensive, evidence-based systematic appraisal of the advancements and limitations of detection, prognosis, and interventions for CHR-P individuals and to fo...
Preprint
Full-text available
Background Schizophrenia is a heterogeneous neurodevelopmental disease involving cognitive and motor impairments. Motor dysfunctions, such as eye movements or neurological soft signs (NSS), are proposed as endophenotypic markers. Methods Machine-learning method applied on oculomotor performances using comprehensive testing with prosaccades, antisac...
Article
Résumé Les lipides membranaires jouent un rôle important dans le fonctionnement cérébral et peuvent désormais être étudiés de manière précise. Cette revue vise à familiariser le lecteur avec les lipides membranaires et les conséquences de leurs anomalies dans les troubles du spectre schizophrénique. Nous nous intéresserons aux données concernant le...
Article
Autism spectrum disorder (ASD) and schizophrenia (SCZ) are neurodevelopmental disorders with partly overlapping clinical phenotypes including sensorimotor impairments. However, direct comparative studies on sensorimotor control across these two disorders are lacking. We set out to compare visuomotor upper limb impairment, quantitatively, in ASD and...