Emory University - Department of Epidemiology, Emory University - Department of Epidemiology, University of Cape Town (UCT), University of Cape Town (UCT) - Neuroscience Institute, University of Manitoba, affiliation not provided to SSRN, University of Cape Town (UCT), University of Cape Town (UCT) - Department of Pediatrics and Child Health, University of Cape Town (UCT) - Department of Pediatrics and Child Health, University of British Columbia (UBC) - Centre for Molecular Medicine and Therapeutics, University of Cape Town (UCT) - Department of Pediatrics and Child Health, University of Cape Town (UCT) - Neuroscience Institute and Emory University - Department of Epidemiology