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The purpose of this review is to summarize the current state of knowledge on how nongenetic factors occurring before, during, or soon after birth are related to schizophrenia. Schizophrenia is a complex psychiatric illness with a varied clinical presentation that has both environmental and genetic origins and that may result from insults to the nervous system that occur throughout development. In line with this, several endogenous (internal) and exogenous (external) nongenetic factors of pregnancy and birth have been related to an increased risk for schizophrenia in later life. These factors include maternal diabetes, low birth weight, older paternal age, winter birth, and prenatal maternal stress, among others. Although each of these nongenetic factors alone slightly increases the risk for schizophrenia, risk increases when these factors combine with each other and with other risk factors. The mechanisms that link each specific risk factor with the occurrence of schizophrenia remain largely unknown. In order to build better models of the illness, researchers will have to address the question of how environmental and genetic risk factors work together in increasing risk and explore to what extent certain underlying risk factors may explain different aspects of the disease. [ABSTRACT FROM AUTHOR]

Introduction. Many recent studies have found that, although schizophrenia patients tend to display diminished facial expressions of emotion, they report levels of emotional experiences that are similar to those of controls. Although these findings are very informative, it is unknown whether such dissociation exits for other modalities such as verbal expression of emotion. The purpose of this study was to investigate the association between the use of emotion words during a free speech task and subjective experience of emotion in schizophrenia patients and controls. Methods. Speech samples of 48 schizophrenia patients and 48 nonpsychiatric control individuals were compared on the type and amount of emotional words used, as well as on the level of self-reported stress experienced while providing descriptions of themselves. Results. Groups did not differ in the amount or type of emotion words uttered during the free speech task. Patients, however, found the task more stressful than controls. Emotion word use and subjective emotional experience were not related in either group. Conclusions. Results do not fully support prior findings, but are consistent with the notion of a lack of correspondence between the expression and experience of emotion. [ABSTRACT FROM AUTHOR]

Unlabelled: Several studies have shown that patients with schizophrenia are more likely to be born in the winter and early spring than at any other time of the year. Furthermore, some studies have reported that winter-born patients differ from non-winter-born patients in terms of risk factors, symptoms, sensory abnormalities and brain morphology. Associations between season of birth and premorbid adjustment (PMA), however, are still unclear.Objective: The main purpose of this study was to determine whether winter-born and non-winter-born schizophrenia patients differ in terms of PMA and to examine how family history of schizophrenia-spectrum disorders may influence the association.Method: Data on four PMA dimensions (attention, internalizing, externalizing and social problems) and family history were gathered from 37 schizophrenia patients (26 males and 11 females) and their mothers.Results: Non-winter-birth and a positive family history of schizophrenia-spectrum disorders were associated with worse PMA. Results suggest that, although no significant interaction was found, season of birth and family history appear to work together in explaining distinct dimensions of PMA. [ABSTRACT FROM AUTHOR]