Obstetric complications and transition to psychosis in an 'ultra' high risk sample

Objective: An association between birth and pregnancy complications and the later development of schizophrenia has been described for decades and obstetric complications (OCs) have been proposed as a vulnerability marker for psychosis in line with the neurodevelopmental hypothesis of psychotic disorders. Previous studies of OCs have focused on established schizophrenia. In this study, the association between OCs and the development of psychotic disorder was studied in a group of 74 young people identified as being at very high risk for the first onset of psychosis. Method: The 'ultra' high risk (UHR) cohort was identified by the presence of subthreshold psychotic symptoms, or a combination of first-degree relative with a psychotic disorder and recent functional decline. Thirty-eight per cent of the cohort developed an acute psychotic episode over the 12-month period after recruitment. As a component of a larger research study, the level of OCs experienced by the UHR cohort was assessed at intake. Results: Obstetric complications were not associated with the later development of psychosis in the UHR group included in this study. Conclusions: This study does not support a role for OCs as a risk factor for the later development of psychosis; however, we cannot conclude that they should be completely ignored as a candidate risk factor for onset of psychosis. A number of weaknesses of the study suggest that it may be premature to dismiss OCs as a risk factor for the development of psychosis and further research is urged in this area.