[1] Qatar Univ, Social & Econ Survey Res Inst, SESRI, POB 2713, Doha, Qatar
[2] Qatar Univ, Coll Hlth Sci, Dept Publ Hlth, POB 2713, Doha, Qatar
[3] Qatar Univ, Coll Med, Dept Populat Med, POB 2713, Doha, Qatar
[4] Univ Sheffield Western Bank, Sch Med, Dept Neurosci, Sheffield S10 2TN, England
[5] Hamad Med Corp, POB 3050, Doha, Qatar
[6] Qatar Univ, Coll Med, Doha, Qatar
[7] Univ Manchester, Div Psychol & Mental Hlth, Manchester, England