1. National Rehabilitation Centre Abu Dhabi United Arab Emirates
2. Addictions Department, Division of Academic Psychiatry, Institute of Psychiatry, Psychology and Neuroscience King's College London UK
3. Department of Neuropsychiatry, Faculty of Medicine Assuit University Egypt
4. Faculty of Medicine, Institute of Psychiatry Ain Shams University Egypt
5. World Health Organization, Eastern Mediterranean Regional Office Cairo Egypt
6. Faculty of Medicine Cairo University Egypt
7. Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences Khalifa University P.O.Box 127788 Abu Dhabi United Arab, Emirates
8. Medical Statistics Team University of Aberdeen UK