Post Traumatic Stress Disorder (PTSD) – A Primer on Neurobiology and Management
Psychological trauma involves the witnessing of a traumatic or life-threatening event directly to yourself or others. The individual is likely to experience intense fear, horror, and helplessness, which can result in a permanent or transient psychological wound characterised by physical, cognitive, emotional and behavioural changes.
For most, the trauma is acute and transient and results in minimal functional impairment. The psychological trauma can be classified into three clusters of symptoms. These include:
- Re-experience – Flashbacks, nightmares, and intrusive thoughts
- Hyper-arousal – Insomnia, agitation, irritability, impulsivity, and anger
- Avoidance – Numbing, withdrawal, confusion, dissociation, and depression
For some, however, the syndrome persists, and this is termed post-traumatic stress disorder (PTSD). A PTSD diagnosis was originally considered a normal response to an extreme situation however the presence of symptoms for an extended period of time beyond one month is indicative of an abnormal adaptation in the brain.
The prevalence of PTSD varies across countries. It occurs in 5-10% of the population and has a 2:1 female to male ratio. The gender bias may be a result of a combination of a greater propensity to lifetime violence exposure and genetic vulnerability (variation in the ADCYAP1R1 (pituitary receptor) gene). 
In military populations, the risk is more significant. For example, 10 years after the Vietnam war the rates of current PTSD went up to 28% in those who had experienced combat exposure. Recent analysis showed that 40 years after the end of the war, 11% of Vietnam veterans are experiencing PTSD symptoms. 
In civilian population samples, the rates vary from 0.2%-3.8%. A number of factors such as social supports, trauma type, and severity affect prevalence.