Excess in the spring and deficit in the autumn in birth rates of male schizophrenic patients in Italy: potential role of perinatal risk factors.

The aim of this study was to evaluate whether there were different seasonal variations of births in an Italian population of patients with schizophrenia, with other psychotic disorders, and with personality disorders than in the general population. Birth dates of 1270 patients admitted to one university psychiatric unit in Rome between 1990 and 2003, with a diagnosis of schizophrenia, other psychotic disorder (OPD) and personality disorder/cluster A (PD) were analyzed according to seasonal variation. A significant excess of births in spring (with a peak in May) and a deficit in autumn (with a trough in October) was found in the sample of male schizophrenics (n = 506). No statistically significant variations were found in either the sample of female schizophrenics (n = 88) or in the combined sample with OPD and PD (n = 676). The findings serve to strengthen the existing hypotheses that schizophrenia is related to environmental factors acting on the development of the central nervous system intrauterinely.

Bersani G ，Pucci D ，Gherardelli S ，Conforti F ，Bersani I ，Osborn JF ，Hansen V ，Pancheri P ... -  《-》

[Seasons of birth of schizophrenic patients. Retrospective study of a hospitalized population in Tunisia].

Epidemiological research concerning the seasons of births of schizophrenics show for the greatest part that there's an excess of births in winter and in the beginning of spring. Research about the environmental theories of schizophrenia suggest that there would exist one or many seasonal environmental factors affecting the foetus and the neonate, and which would be likely to increase the risk of a subsequent development of schizophrenia. As no research concerning this subject have been published so far in Africa, the writers propose to study the distribution of births of a population of schizophrenics born in Tunisia in comparison to the general population and to compare it to a group of patients hospitalized because of major affective disorders. The results achieved show a significant decrease in the number of schizophrenics births during the third trimester and an excess of births during the month of october, the risk being greater in the case of disorganized schizophrenia. The greater risk for people born in october to develop subsequently schizophrenia is not found in the case of major affective disorders but it is found rather in the case of schizo-affective disorders. More over, we notice a decrease in the number of births during the month of July for the patients presenting major affective disorders and for those presenting schizo-affective disorders. Results seem to demonstrate that there would exist seasonal environmental factors specific to North Africa which are likely to affect the subsequent appearance of schizophrenic disorders. A particular interest should be given to viral infectious to enteroviruses which are responsible for summer diarrhea in Tunisia.(ABSTRACT TRUNCATED AT 250 WORDS)

Khiari G ，Cheour M ，Ben Nasr S ，Bouzid R ，Tabbane K ，Douki S ... -  《ENCEPHALE-REVUE DE PSYCHIATRIE CLINIQUE BIOLOGIQUE ET THERAPEUTIQUE》

Winter birth excess in schizophrenia and in non-schizophrenic psychosis: sex and birth-cohort differences.

Despite the fact that association between winter birth excess and schizophrenia in the northern Hemisphere is well established, possible sex or birth-cohort differences in this winter birth excess remain unclear. We aimed to evaluate sex and birth-cohort differences in the seasonal birth distribution of patients with schizophrenia or non-schizophrenic psychosis. The sample included 321 ICD-10 schizophrenia and 294 non-schizophrenic psychosis patients consecutively admitted into a psychiatric hospitalization unit in Granada, southern Spain, during a nine-year period (1998-2006). The distribution of births among the general population born over the same period as the patients was calculated. Among schizophrenia males (n=258), it was possible to demonstrate that the observed proportion of winter birth (December, January or February) was significantly higher than expected. Among schizophrenia females (n=63), although proportions were as in males and the effect size of the difference between observed and expected winter births was not lower than for men, only a statistical trend could be demonstrated. Among patients with non-schizophrenic psychosis, the observed proportion of winter birth was significantly higher than expected in women, but not in men. The sex-adjusted proportion of winter birth among schizophrenia patients born in the 1940's (a time period characterized by poor economy and widespread food restrictions because of the Spanish post-civil-war period) was significantly higher than among those born later; a difference that does not occur among patients with a non-schizophrenic psychosis. Among schizophrenia patients born in winter there appear to be slight sex-differences and strong birth-cohort differences, possibly due to epidemiological factors such as poverty or maternal nutritional deprivation. Epidemiological findings related to winter birth excess among patients with schizophrenia must be identified in longitudinal studies.

Martínez-Ortega JM ，Carretero MD ，Gutiérrez-Rojas L ，Díaz-Atienza F ，Jurado D ，Gurpegui M ... -  《-》

[Early familial and environmental processes in schizophrenia. Importance of premorbid personality evaluation].

According to the neurodevelopmental hypothesis, antenatal aggressions (hypoxia and seasonal viral infections) could increase the risk of schizophrenia in adulthood as shown by an excess of obstetric complications and births in winter--spring in schizophrenic patients. As schizoid and schizotypal personality disorders are genetically linked to schizophrenia, we wanted to verify whether such disorders in the premorbid period in schizophrenic patients could be markers of a more genetic and less environmental sub-type of schizophrenia. Therefore, the aim of this study was to assess schizoid and schizotypal premorbid personality disorders (PPD) in 60 schizophrenic patients, and to assess the weight of familial and environmental factors according to the diagnosis of PPD. 41.7% of patients (25/60) had a schizoid or schizotypal PPD. Compared with patients without PPD, patients with PPD had more often schizophrenia spectrum disorders in first degree relatives (33.3% vs 14.7%, NS), less often obstetric complications (20.8% vs 50.0%, p < 0.05) and were less often born in the first half-year (44.0% vs 68.6%, p = 0.05). So, we showed a non significant positive association between schizoid--schizotypal PPD and family history of schizophrenia spectrum disorders, and a significant negative association between PPD and environmental factors: obstetric complications (OC) and birth in winter-spring. So, the absence of PPD could enable us to identify a sub-group of patients in whom environmental factors play a major role. Moreover, the relations between genetic factors and PPD seem to be complicated. Nevertheless, the notion of PPD could give information about the kind of genetic factors implicated in schizophrenia.

Chabot B ，Germain-Robin S ，Petit M ，Dollfus S ... -  《ENCEPHALE-REVUE DE PSYCHIATRIE CLINIQUE BIOLOGIQUE ET THERAPEUTIQUE》

[Analysis of the seasonality of birth effect in schizophrenic patients in Poland with the application of the seasonal decomposition method].

Bembenek A 《Psychiatria Polska》