Giuseppe D'Andrea

University of Montreal Hospital Research Centre | CRCHUM · Neuroscience

Background Psychosis rates are higher among some migrant groups. We hypothesized that psychosis in migrants is associated with cumulative social disadvantage during different phases of migration. Methods We used data from the EUropean Network of National Schizophrenia Networks studying Gene-Environment Interactions (EU-GEI) case–control study. We...

Background: Child maltreatment (CM) and migrant status are independently associated with psychosis. We examined prevalence of CM by migrant status and tested whether migrant status moderated the association between CM and first-episode psychosis (FEP). We further explored whether differences in CM exposure contributed to variations in the incidenc...

Background Incidence of first-episode psychosis (FEP) varies substantially across geographic regions. Phenotypes of subclinical psychosis (SP), such as psychotic-like experiences (PLEs) and schizotypy, present several similarities with psychosis. We aimed to examine whether SP measures varied across different sites and whether this variation was co...

Background Urbanicity is a well‐established risk factor for psychosis. Our recent multi‐national study found an association between urbanicity and clinical psychosis in Northern Europe but not in Southern Europe. In this study, we hypothesized that the effect of current urbanicity on variation of schizotypy would be greater in North‐western Europe...

The rising prevalence and legalisation of cannabis worldwide have underscored the need for a comprehensive understanding of its biological impact, particularly on mental health. Epigenetic mechanisms, specifically DNA methylation, have gained increasing recognition as vital factors in the interplay between risk factors and mental health. This study...

Several studies have highlighted increased psychosis risk in migrant and minority ethnic populations. Migration before age 18 appears to increase risk, but further evidence is required. We investigated this issue in a European case-control study. We hypothesized that migration during two key socio-developmental periods, childhood and adolescence, w...

The rising prevalence and legalization of cannabis worldwide have underscored the need for a comprehensive understanding of its biological impact, particularly on mental health. Epigenetic mechanisms, specifically DNA methylation, have gained increasing recognition as vital factors in the interplay between risk factors and mental health. This study...

This study investigated if the association between childhood maltreatment and cognition among psychosis patients and community controls was partially accounted for by genetic liability for psychosis. Patients with first-episode psychosis (N = 755) and unaffected controls (N = 1219) from the EU-GEI study were assessed for childhood maltreatment, int...

Background Childhood adversity and cannabis use are considered independent risk factors for psychosis, but whether different patterns of cannabis use may be acting as mediator between adversity and psychotic disorders has not yet been explored. The aim of this study is to examine whether cannabis use mediates the relationship between childhood adve...

Background: While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis. Methods: We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case-control study. 558 first-...

Background Tobacco is a highly prevalent substance of abuse in patients with psychosis. Previous studies have reported an association between tobacco use and schizophrenia. The aim of this study was to analyze the relationship between tobacco use and first-episode psychosis (FEP), age at onset of psychosis, and specific diagnosis of psychosis. Met...

Background: Antipsychotic treatment resistance affects up to a third of individuals with schizophrenia, with recent research finding systematic biological differences between antipsychotic resistant and responsive patients. Our aim was to determine whether cognitive impairment at first episode significantly differs between future antipsychotic res...

Previous evidence showed significant discrepancies in psychiatric services utilization between migrants and reference populations. Our study aims were to evaluate incidence and characteristics of psychiatric hospitalizations of migrant patients compared with reference populations and to assess how the COVID-19 pandemic affected admissions. All pati...

Background and Hypothesis It is argued that availability of diagnostic models will facilitate a more rapid identification of individuals who are at a higher risk of first episode psychosis (FEP). Therefore, we developed, evaluated, and validated a diagnostic risk estimation model to classify individual with FEP and controls across six countries. S...

Objective: There is evidence of a bidirectional association between COVID-19 disease and psychiatric disorders. We aimed to assess whether exposure to psychotropic medications prior to hospitalization was associated with mortality or discharge within 30 days after hospital admission. Methods: In this prospective study, we included all individual...

Introduction: Our aim was to, firstly, identify characteristics at first-episode of psychosis that are associated with later antipsychotic treatment resistance (TR) and, secondly, to develop a parsimonious prediction model for TR. Methods: We combined data from ten prospective, first-episode psychosis cohorts from across Europe and categorised p...

Introduction Numerous evidences point out how migrants use health services differently than the natives. Migrants turn more frequently to the ED for psychiatric problems and less to territorial psychiatric services than the native population. Other differences can be found in terms of diagnosis, type of discharge, type of hospitalization. Objectiv...

Background and hypothesis Evidence suggests that childhood maltreatment (ie, childhood abuse and childhood neglect) affects educational attainment and cognition. However, the association between childhood maltreatment and Intelligence Quotient (IQ) seems stronger among controls compared to people with psychosis. We hypothesised that: the associatio...

Importance About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizo...

Importance: About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schiz...

Migration is a global phenomenon of topical interest. The way that moving from one sociocultural context to another affects the mental health of individuals has been the object of many studies. A sizable body of literature shows that migration is associated with an increased risk of developing mental disorders, particularly psychosis. The higher in...

Diagnostic categories do not completely reflect the heterogeneous expression of psychosis. Using data from the EU-GEI study, we evaluated the impact of schizophrenia polygenic risk score (SZ-PRS) and patterns of cannabis use on the transdiagnostic expression of psychosis. We analysed first-episode psychosis patients (FEP) and controls, generating t...

Background Melnick–Needles syndrome and periventricular nodular heterotopia are two usually mutually exclusive phenotypes of F-actin-binding cytoskeletal phosphoprotein Filamin-A mutations. Melnick–Needles syndrome is a rare X-linked condition that is lethal in males and shows great phenotypic variability in affected females. It is caused by mutati...

Migration is an ever-painful event which may expose personal vulnerabilities: individuals may experience the loss of the symbolic, cultural, and social reference framework, the arrest of the ongoing processes of identity formation and reproduction, and the paralysis of temporalization. The scientific research on mental disorders in the migratory an...

Background In this review, we aimed to evaluate the association between language proficiency (LP) and the prevalence and severity of mental disorders in migrants. Secondarily, we aimed to consider whether sociodemographic and migration-related factors may affect the correlation between LP and mental disorders. Methods MEDLINE, PsycArticles, EMBASE...

Background: Migrants present high rates of psychosis. A better understanding of this phenomenon is needed. Methods: We conducted a multicentre First-Episode Psychosis (FEP) prospective study over two years (January 2012-December 2013) to evaluate first-generation migrants presenting with FEP at the participating Community Mental Health Centers (...

Duration of untreated psychosis (DUP) is associated with clinical outcomes in people with a diagnosis of first-episode psychosis (FEP), but factors associated with length of DUP are still poorly understood. Aiming to obtain insights into the possible biological impact on DUP, we report genetic analyses of a large multi-center phenotypically well-de...

Introduction Child abuse is associated with a wide range of mental disease including psychotic disorders. Few studies have investigated the role of child abuse in contributing to increase the risk of psychosis in migrant population. Objectives To explore the risk of first episode psychosis (FEP) in migrants and natives for each type of trauma i.e....

Objective: According to the gene-environment interaction model the pathogenesis of psychosis relies on an adverse neuro-socio-developmental pathway. Perinatal stress represents an important risk factor for the development of psychosis because of the increasingly evident interference with socio-neuro-development in the earlier phases of life. We ai...

Aim To estimate the association between the inpatient admissions and Emergency Department (ED) visits before age of 18 years and adulthood‐onset first‐episode psychosis (FEP). Methods We conducted a FEP incidence and case–control study and calculated the odds ratios (ORs) for incident FEP associated with inpatient admissions and ED visits prior to...