1 University of Oxford, Department of Psychiatry, Oxford OX3 7JX, UK.
2 University of Oxford, Department of Psychiatry, Oxford OX3 7JX, UK; MRC/Wits Rural Public Health and Health Transitions Research Unit [Agincourt], School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.
3 MRC/Wits Rural Public Health and Health Transitions Research Unit [Agincourt], School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; PRICELESS SA [Priority Cost Effective Lessons in System Strengthening South Africa], School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa. Electronic address: Karen.Hofman@wits.ac.za.