Influence of Environmental Factors and Schizophrenia (Envschi)

Influence of Environmental Factors on the Prevalence, Risk and the Clinical Manifestations of Schizophrenia

Institut national d'étude démographique (INED), CPN (INSERM U894) CH Sainte-Anne - Paris, Institut National de la Santé Et de la Recherche Médicale, France, Fondation FondaMental, University Hospital, Clermont-Ferrand

Schizophrenia is a chronic and severe mental disorder with a lifetime prevalence of about 1 per cent, the symptoms can be very disabling and causing a heavy medical and socioeconomic. There are significant variations from one population to another. Clinical manifestations of schizophrenia (symptoms, evolution, severity of disability) are highly variable. This variability, both epidemiological and clinical, is due to genetic and environmental factors. Environmental factors may be either risk factors or modifying factors (changing clinical presentation but do not alter the risk of disease) for schizophrenia. Environmental risk factors have been identified (eg: urbanity, cannabis, migration), but the investigators don't know neither the components directly responsible, nor the mechanisms by which they increase the risk of schizophrenia. To date, there is no study has systematically evaluated the role of environmental modifying factors in schizophrenia. Environmental factors may be individual, unique to each person (eg cannabis, migration.), or population-based (eg ethnic density, socio-economic difficulties.) The identification/ identifying of environmental risk factors or modifiers, both individual and population, may have theoretical implications (understanding of etiopathogenic mechanisms) and practical (implementation of preventive measures). The potential effectiveness of preventive measures is even greater than the risk attributable to certain environmental factors is important. Most studies on environmental factors in schizophrenia were conducted in Anglo-Saxon countries and northern Europe, but no study of these risk factors has been conducted in France. There are important differences environment based on study populations, these results are not generalizable to other countries, including France.

The prevalence of schizophrenia (according to Diagnostic and Statistical Manual of Mental Disorders (DSM IV)) will be estimated from the census population-unit (unit TRIRIS INSEE)

The frequency of populational risk factors (insecurity, disorganization and density of migrants) will be assessed from the variables of INSEE

The frequency of individual risk factors (migration, cannabis, seasonality of birth, childhood trauma, social environment) will be measured from standardized assessments

Inclusion Criteria: All subjects Age > 18 years Somatic state / condition and level of understanding (language, intellectual level) compatible with the data collection (interview, self-administered questionnaires) Patients Diagnosis of schizophrenia according to DSM-IV criteria Living in catchment areas Non-Inclusion Criteria: All subjects Not affiliated to the social security scheme inability to provide informed consent Decompensated schizophrenic underway Relatives Protective Measures (tutor, curator) Exclusion criteria: Patients The diagnosis of psychotic disorder is not confirmed by the synthesis of all clinical data