For PTSD to be diagnosed officially, a person has to meet specific criteria, or requirements, and show specific symptoms. These requirements are listed in the "Diagnostic and Statistical Manual-IV-TR" (usually called the DSM-IV-TR). Written by the American Psychiatric Association (APA), the DSM-IV-TR (DSM, 4th Edition, Text Revision) lists all of the mental health conditions that are recognized by the APA, and sets out the official requirements that have to be met for each condition to be diagnosed.