Traumatic stressors
The World Health Organization classification ICD-11 defines PTSD as follows: (1)
Post-traumatic stress disorder (PTSD) may develop following exposure to an extremely threatening or horrific event or series of events. It is characterised by all of the following:
- Re-experiencing the traumatic event or events in the present in the form of vivid intrusive memories, flashbacks, or nightmares. Re-experiencing may occur via one or multiple sensory modalities and is typically accompanied by strong or overwhelming emotions, particularly fear or horror, and strong physical sensations.
- Avoidance of thoughts and memories of the event or events, or avoidance of activities, situations, or people reminiscent of the event(s).
- Persistent perceptions of heightened current threat - for example, as indicated by hypervigilance or an enhanced startle reaction to stimuli such as unexpected noises.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) draws a distinction between acute stress disorder (also known as combat and operational stress reaction in the military; symptoms are present for less than1 month) and PTSD (where symptoms are present for more than 1 month). (2)
PTSD may be:
Both natural and human-made traumatic events are capable of evoking PTSD symptoms. Some typical traumatic events include: (3)
- serious accidents
- military combat
- violent personal assault (sexual assault, physical attack, abuse, robbery, mugging)
- being taken hostage
- terrorist attack
- being a prisoner-of-war
- natural or man-made disasters
- being diagnosed with a life-threatening illness
Reference:
- International Classification of Diseases 11th Revision; World Health Organization, 2019/2021
- American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed., text revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.
- The Royal College of Psychiatrists. Post Traumatic Stress Disorder (PTSD). 2025 (online)