K Lommerse1, M Knight2, M Nair2, C Deneux-Tharaux3, T van den Akker2,4. 1. Department of Psychiatry, Haaglanden Medical Centre, The Hague, the Netherlands. 2. National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK. 3. INSERMU1153, Obstetric, Perinatal, and Paediatric Epidemiology Research Team, Centre for Epidemiology and Statistics Sorbonne Paris Cité, Paris Descartes University, Paris, France. 4. Department of Obstetrics, Leiden University Medical Centre, Leiden, the Netherlands.