[1] Univ Cape Town, Groote Schuur Hosp, Dept Psychiat & Mental Hlth, J Block, ZA-7925 Cape Town, South Africa
[2] Brown Univ, Dept Behav & Social Sci, Ctr Alcohol & Addict Studies, 121 South Main St,Box G-S121-4th Floor,Room 406, Providence, RI 02912 USA
[3] Red Cross War Mem Childrens Hosp, Dept Paediat & Child Hlth, Cape Town, South Africa
[4] MRC, Unit Child & Adolescent Hlth, Cape Town, South Africa
[5] MRC, Unit Anxiety & Stress Disorders, Cape Town, South Africa