Boysen, Guy A., and Ashley Ebersole. "Expansion of the Concept of Mental Disorder in the DSM-5." The Journal of Mind and Behavior, vol. 35, no. 4, Autumn 2014, pp. 225–43, www.jstor.org/stable/43854371.
"Mental Health Information." National Institute of Mental Health, U.S. Department of Health and Human Services, www.nimh.nih.gov/health/topics/index.shtml. Accessed 30 June 2018.
Walton, Alice G. "Why More Americans Suffer from Mental Disorders Than Anyone Else." The Atlantic, 4 Oct. 2011, www.theatlantic.com/health/archive/2011/10/why-more-americans-suffer-from-mental-disorders-than-anyone-else/246035.