1. What Is Depression?https://www.psychiatry.org/patients-families/depression/what-is-depression
2. Depression and other Common Mental Health Disorders Global Health Estimateshttp://www.who.int/news-room/fact-sheets/detail/depression
3. The Economic Burden of Adults With Major Depressive Disorder in the United States (2005 and 2010)
4. Depression in adults: Recognition and Managementhttps://www.nice.org.uk/guidance/cg90/chapter/2-Research-recommendations
5. Clinical Practice Review for Major Depressive Disorderhttps://adaa.org/resources-professionals/practice-guidelines-mdd