1. South African Medical Research Council; Alcohol, Tobacco and Other Drug Research Unit; Francie van Zyl Drive, Tygerberg, 7505, Parow Cape Town Western Cape South Africa 7505
2. South African Medical Research Council; Alcohol Tobacco and Other Drug Research Unit; Francie van Zyl Drive, Tygerberg, 7505, Parow Cape Town Western Cape South Africa 7505
3. University of Cape Town; Department of Psychiatry and Mental Health; Cape Town South Africa
4. University of Cape Town; Department of Psychology; Rondebosch Cape Town Western Cape South Africa 7701
5. Stellenbosch University; Centre for Evidence-based Health Care, Faculty of Medicine and Health Sciences; Francie van Zijl Drive Tygerberg Cape Town South Africa 7505
6. South African Medical Research Council; South African Cochrane Centre; PO Box 19070 Tygerberg Western Cape South Africa 7505