Swedish High-Risk Study: Sample Characteristics at Age 6

Abstract

High-risk offspring of women with a history of nonorganic psychosis and control offspring of women with no history of psychosis were studied from the mother's pregnancy through 2 years of age and followed up at 6 years of age. The mothers tended to be older and have somewhat higher parity than did Swedish mothers in general. Sample attrition during the 6-year longitudinal period was significantly higher in the high-risk than the control sample, and selective in both groups. A limited set of early-life variables, investigated prospectively, was selected for studying the antecedents of mental disturbance in the offspring at 6 years. In the high-risk group, disturbance in the offspring was related to maternal anxiety during pregnancy, negative maternal attitude toward pregnancy, and maternal psychotic condition during the period from 6 months to 2 years post-partum, and tended to be related to low social class, male child, active maternal-mental disturbance during pregnancy, prolonged labor and low Apgar score at delivery, neonatal neurological abnormality, and anxious attachment to the mother at 1 year of age. None of these relationships (except low social class) appeared in the control group, and no significant antecedents of mental disturbance in control offspring were found among the limited set of variables studied in these analyses.

Cognitive and Neuroplasticity Mechanisms by Which Congenital or Early Blindness May Confer a Protective Effect Against Schizophrenia

“…In addition, odor perception is important in forming bonds with peers in childhood (Sullivan, 2000). It is therefore interesting that risk for schizophrenia is associated with problems in maternal attachment (demonstrated at 3 days, 1, and 6 years of age; Naslund et al, 1984; Persson-Blennow et al, 1984; McNeil and Kaij, 1987), increased stress reactivity (Myin-Germeys and van Os, 2007), and fewer peer relationships (Schenkel and Silverstein, 2004), as well as olfactory processing deficits (Brewer et al, 2003). …”

Obstetric complications in histories of monozygotic twins discordant and concordant for schizophrenia

“…The importance of a genetic component in the development of schizophrenia is now indisputable (1, 2). Nevertheless, modern twin studies find concordance rates for schizophrenia to be as low as 30% in monozygotic (MZ) twins (3), suggesting that environmental factors may act as moderators of genetic influence and/or as alternative etiological factors (4). As MZ twins share 100 % of their genes, the study of MZ twin pairs discordant for schizophrenia provides a powerful strategy for the examination of potential environmental etiological factors (5).…”

Women with nonorganic psychosis: psychiatric and demographic characteristics of cases with versus without postpartum psychotic episodes

“…While a majority of the sample had had at least two reproductions, some of the low-parous women with no PPP to date may possibly develop a PPP in later reproductions, thus moving from the Never-PPP subgroup to the Both-PPP/Other subgroup. (The current index sample was older and had higher parity than most reproducing women in the Swedish population (6), suggesting that the current data likely covered a majority of most cases' reproductions.) Similarly, lifetime follow-up of the cases' psychiatric courses might potentially identify later nonPPP episodes among women now classified as having "only PPPs", providing a potential movement from the Only-PPP subgroup to the Both-PPP/Other subgroup.…”