[Epidemiology of schizophrenic disorders].
The prevalence of schizophrenic disorders in the general population is 1%, that is, in France, approximately 40000 people, given the age group concerned. The sex ratio is one. The first episode occurs between the ages of 15 and 25 years in men, a little later in women. 90% of patients treated for schizophrenia are aged from 15 to 55 years. The short-term course is marked by a relapse rate after the first episode estimated at 20-40%. The long-term evolution is marked by substantial excess mortality, a suicide rate of 10-20% and an overall decrease of approximately 10 years in life expectancy. Only 10% of patients will have an outcome including full autonomy. The socioeconomic impact is therefore considerable, with a mean cost of management estimated at 15000 Euros per year. Genetic factors affect vulnerability or predisposition to schizophrenia. Accordingly a first-degree relative of a schizophrenic patient has a risk 5 to 10 times higher of developing the disease than does a person with no affected relatives. This risk is not one of simple Mendelian transmission but rather vulnerability, which implies the intervention of several genes. Some environmental factors have also been identified, including exposure to influenza virus during the gestational period (between the 4th and 7th month of pregnancy). This finding reinforces the hypothesis of a neurodevelopmental origin of schizophrenia. Finally, among other associated factors, regular cannabis use appears to quadruple the risk of disease.
Service de psychiatrie d'adultes, Hôpital Albert Chenevier, Créteil. stephane.hautecouverture@ach.ap-hop-paris.fr
Stéphane
S
Hautecouverture
Frédéric
F
Limosin
Frédéric
F
Rouillon
D000293:Adolescent; D000328:Adult; D004777:Environment; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology* / Q000517:prevention & control; D012959:Socioeconomic Factors