Hence, PTSD is distinct from functional somatic syndromes, such as irritable heart or DAH, which are defined by the presence of multiple, clinically-significant somatic symptoms but do not require overt psychological experiences such as nightmares or avoidant behaviour. PTSD, first recognized as a legitimate psychiatric diagnosis in 1980, 7 is defined in psychological terms as a disorder of traumatic memory, featuring nightmares, intrusive recollections and flashbacks (which overlap with the normal ways in which veterans remember their experiences), but also behaviourally since these features lead to avoidance and impaired social interaction. This lack of clarity is hardly surprising since both can arise in the context of warfare. One area of understandable confusion is the relationship between conventional psychiatric disorders, in particular post-traumatic stress disorder (PTSD), and syndromes characterized by medically unexplained symptoms. Without demonstrable organic cause, war syndromes have attracted diverse causal explanations, ranging from pressure on the arteries of the chest, constitutional inferiority, toxic exposure, bacterial infection to microscopic cerebral haemorrhage.

6 Furthermore, they are not easily interpreted using accepted psychiatric classifications. 5 Despite popular claims to the contrary, no simple biomedical aetiology has been discovered to account for these disorders, hence the term “medically unexplained”. 2 We, among many others, have argued that they should be classified as functional syndromes 3 characterized by medically unexplained symptoms, 4 which include: fatigue, weakness, sleep difficulties, headache, muscle ache and joint pain, problems with memory, attention and concentration, nausea and other gastro-intestinal symptoms, anxiety, depression, irritability, palpitations, shortness of breath, dizziness, sore throat and dry mouth. 1 However, controversy has raged over the nature of particular post-combat disorders such as shell shock, disordered action of the heart (DAH), effort syndrome, effects of Agent Orange and, not least, Gulf War syndrome. The general principle that the experience of combat damages servicemen's long-term physical and mental health is recognized.

War exhaustion victoria 2