Trauma is a term that is widely used and may mean different things to different people. In these Guidelines, we use the word trauma to refer to an extremely threatening or horrific event, or a series of events, in which a person is exposed to, witnesses, or is confronted with a situation in which they perceive that their own, or someone else’s, life or safety is at risk [10, 11]. Examples of potentially traumatic events include, but are by no means limited to, being involved in a road traffic accident; experiencing or being threatened with physical or sexual assault; being in a life-threatening car or other form of accident; combat exposure or being in a place of war or conflict; or witnessing any of these events. The most important factor in understanding a person’s experience of an event is whether or not they perceived it to be a traumatic event; events that may be traumatic to some people may be perceived as relatively minor, and vice versa.
Most people will experience some emotional or behavioural reactions following exposure to a traumatic event such as anxiety or fear, aggression or anger, depressive or dissociative symptoms. These emotional and behavioural responses are to be expected and are a completely normal response to an adverse event. For the majority of people, these reactions will subside and/or reduce in intensity over time without the need for any intervention; for some people, however, these reactions may be prolonged, leading to significant distress, as well as impairment in social, occupational and other areas of functioning [102, 156, 157].