1. World Health Organization. Mental Health Depression. Available from: http://www.who.int/mental_health/management/depression/en/. [Last cited on 2016 Jan 11].
2. The Global Burden of Disease, 2010 Update. Department of Health Statistics and Informatics in the Information, Evidence and Research Cluster of WHO. Geneva: WHO Press, World Health Organization; 1995.
3. O'Donnell JM, Shelton RC. Drug Therapy of Depression and Anxiety Disorders. In: Brunton LL, Chabner BA, Knollmann BC, editors. Goodman and Gilman's the Pharmacological Basis of Therapeutics. 12th ed. New York, USA: The McGraw-Hill Companies Inc.; 2011. p. 397-415.