By definition of DSM-IV
(APA, 2000), PTSD always follows a traumatic event which causes intense fear and/or helplessness in an individual. Symptoms are divided into clusters that include re-experiencing the trauma, obsessive thoughts, and flashbacks, avoidance and increased anxiety. The DSM-V work group proposed a few revisions to the definition of PTSD such as specifying sexual assault as a traumatic event, and also to restructure the symptom clusters to highlight negative cognitions and mood as a cluster of its own, and adding to it moods like anger and shame, (to DSM-IV's fear and helplessness) and cognitions such as self blame (APA, 2010). These revisions seem to better describe PTSD symptomatology (Yufik, & Simms, 2010) and to take in the feminist criticism of the PTSD definition being biased against sexual assault related PTSD characteristics (Gross, & Graham-Berman, 2006).
APA. (2000). DSM IV TR online version. Retrieved February 17, 2011, from AllPsych Online: http://allpsych.com/disorders/anxiety/ptsd.html
APA. (2010). PTSD work group. Retrieved February 17, 2011, from DSM-5 proposed revoisions: http://www.dsm5.org/ProposedRevisions/Pages/proposedrevision.aspx?rid=165#
Gross, M; Graham-Berman, S A. (2006). Gender, Categories, and Science-as-Usual: A Critical Reading of Gender and PTSD. Violence Against Women , Vol 12 (4) pp. 393-406.
Yufik, T & Simms, L J. (2010). A Meta-Analytic Investigation of the Structure of Posttraumatic Stress. Journal of Abnormal Psychology , Vol. 119, No. 4, 764–776.