What is PTSD?
Post-traumatic stress disorder is what happens when the brain's threat-detection system gets stuck on. After a traumatic event (or a series of them), the alarm doesn't switch off — and a person's day-to-day life ends up organised around staying safe from a threat that may no longer be present.
Around 5–10% of Australians will experience PTSD at some point in their lives, with significantly higher rates in first responders, ADF veterans, and people who have experienced interpersonal violence or childhood trauma [1]. Common features include:
- Re-experiencing — intrusive memories, flashbacks, nightmares.
- Avoidance — of places, people, conversations, or internal experiences that recall the trauma.
- Hyperarousal — being constantly on guard, easily startled, unable to settle.
- Negative cognition and mood — persistent shame, guilt, disconnection, anhedonia.
- Sleep and concentration disruption — particularly difficulty falling asleep, broken sleep, and intrusive thoughts during the day.
Complex PTSD (cPTSD), described by Judith Herman and now formally recognised in ICD-11, captures the additional features that often accompany prolonged or repeated trauma — particularly disturbed self-organisation, persistent shame, and difficulties with relationships.