On the evening of Saturday 31 August 1901, the celebrated French novelist Marcel Proust wrote to his mother with characteristic intimacy, recounting his struggle to quell a severe attack of asthma the previous day. Having suffered from periodic attacks of asthma since the age of nine, Proust was familiar with the range of contemporary treatments for the condition: over the years, he had been prescribed opium, caffeine, iodine, and morphine (which had once been injected by his father, Dr Adrien Proust), his nose had been cauterized numerous times, he had adopted a milk diet, and he had occasionally attempted to relieve both his asthma and his hay fever by visiting health resorts, such as Evian-les-Bains, on the shores of Lake Geneva. However, as his note to his mother suggests, Proust's favoured remedy involved the inhalation of smoke from anti-asthma cigarettes or powders:

The general principle that the experience of combat damages servicemen's long-term physical and mental health is recognized. 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. We, among many others, have argued that they should be classified as functional syndromes characterized by medically unexplained symptoms, 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. Despite popular claims to the contrary, no simple biomedical aetiology has been discovered to account for these disorders, hence the term “medically unexplained”. Furthermore, they are not easily interpreted using accepted psychiatric classifications. 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.