**3. The introduction of PTSD**

Clinicians have recognized the juxtaposition of acute mental syndromes to traumatic events for more than 200 years. Observations of trauma-related syndromes were documented following the Civil War, and early psychoanalytic writers, including Freud, noted the relation between neurosis and trauma (Kaplan & Sadock, 1999).

The American Psychiatric Association (APA) (1952) published the "Diagnostic and statistical manual of mental disorders, first edition, DSM-I'' and included in that edition gross stress reactions. However, the term PTSD was not included in the publications until the DSM-III in 1980 (Jones et al., 2003). It was then revised in the DSM-III-R (1987) and the DSM-IV (1994). According to the DSM-IV diagnostic criteria, PTSD has three core psychopathologies: (a) reexperience, (b) numbness and avoidance, and (c) hyper-arousal. The DSM-IV diagnostic criteria for PTSD allow clinicians to specify if the disorder is chronic, that is, the symptoms have lasted three months or more, or if the disorder exhibits delayed onset, that is, the onset of the symptoms was six months or more after the stressful event (Su, Tsai, Chou, et al., 2010). PTSD is an anxiety disorder that develops after a person has been exposed to a severe, life-threatening trauma. Its symptoms include a re-experiencing or reliving of the event, an avoidance or numbness toward the event, and/or hyper-arousal (American Psychiatric Association, 1994). Accordingly, PTSD is characterized by two special memory phenomena. The first is a facilitated memory of the traumatic event, including flashbacks and nightmares. The second is an inhibited memory involving the inability to voluntarily recall important aspects of the trauma (Hellawell & Brewin, 2002; Thomaes et al., 2009). These observations imply that emotional memory dysfunctions are key components in PTSD, and they include involuntary retrieval such as flashbacks and intrusions, exaggerated and context-independent fear, failure to integrate the trauma as a coherent episode into an autobiographical memory, and impaired fear memory extinction (Wolf, 2008).
