As the world appears to enter a more uncertain period, attention is being paid to the psychological aftermath of terrorism and natural disasters. However, as the language of PTSD has entered the general lexicon, there is a danger of dilution of the meaning of the term and symptoms. Following the terrorist attack in New York on 11 September 2001, probable PTSD was reported in 7.5% of New Yorkers, many of whom had no direct involvement in the attacks (Galea et al, 2003).

Prevalence of PTSD

The prevalence of PTSD within a community will depend to some extent on the prevalence of traumatic events in the life of that community. The National Comorbidity Survey in the USA found the estimated lifetime prevalence of PTSD among adult Americans to be 8%, with women (10%) twice as likely as men (5%) to have PTSD at some point in their lives (Kessler et al, 1995). However, this represents only a small portion of those who have experienced traumatic events: 60% of men and 51% of women reported at least one such event. The most frequently reported traumas were witnessing someone being badly injured or killed, being involved in a natural disaster or life-threatening accident, and combat exposure. In this National Comorbidity Survey (which presents the largest data-set and longest follow-up, albeit with retrospective assessments), the rate of PTSD declined at a relatively constant rate over 12 months, with a more gradual decline over 6 years.