Invited review: post-traumatic stress disorder; a new clinical entity?

Recently a spate of large scale disasters has caught public attention. Survivors of unexpected catastrophes find their lives radically changed. They may develop a characteristic pattern of symptoms in response to their exposure to overwhelming stress. Ten years ago, American psychiatrists introduced a new diagnostic category, post-traumatic stress disorder (PTSD), referring to the range of psychological symptoms survivors demonstrate after extreme trauma (Diagnostic and Statistical Manual of Mental Disorders, APA, Washington D.C.). Although the validity of this syndrome remains debatable, the term PTSD is increasingly in use, a practice likely to continue given its inclusion in the draft edition of ICD 10 (WHO, Geneva). This review looks at the evidence that PTSD describes a specific clinical entity. The historical background to the belief that individuals respond to stress is summarized. The criteria that must be fulfilled and methods of establishing a diagnosis are described. A discussion of aetiological factors and the natural history of the psychological response to stress follows, with reference to clinical management, including the provision of effective intervention for survivors to prevent a full blown stress reaction emerging.