Diagnostic and Statistical Manual of Mental Disorders (DSM)
A manual of diagnostic criteria for mental disorders published by the American Psychiatric Association. The latest version is the DSM-IV; DSM-V is slated for publication in 2012.
Example: After spending several therapy sessions with the woman he is treating and consulting the DSM-IV, the psychologist concludes that his patient is suffering from bipolar disorder.
This website provides all sorts of helpful information about the DSM: http://allpsych.com/disorders/dsm.html
Fournier, G. (2010). Diagnostic and Statistical Manual of Mental Disorders (DSM). Psych Central. Retrieved on June 3, 2015, from http://psychcentral.com/encyclopedia/2008/diagnostic-and-statistical-manual-of-mental-disorders-dsm/