1 National Centre for Register-based Research, Aarhus University, 8210 Aarhus V, Denmark; Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, Aarhus, Denmark. Electronic address: opr@econ.au.dk.
2 CORE-Copenhagen Research Centre for Mental Health, Copenhagen University Hospital, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH), Aarhus, Denmark.