Also an abbreviation for the Diagnostic and Statistical Manual of Mental Disorders, used in psychology. This book categorizes all sorts of psychological issues, and is considered the essential reference for diagnosis. The current version as of this writing is the DSM-IV-TR, 'IV' indicating fourth edition, 'TR' standing for 'Text Revision'. It is published by American Psychiatric Publishing, Inc., who currently have a web page at http://www.appi.org/ if you're interested in more information. See also DSM-IV.