One of the hardest jobs I have to do several times each day is to convince a patient with functional troubles that all the symptoms are due to a nervous interference with the functions of a normal heart and a normal digestive tract. Some of these persons will, of course, have noted that their troubles followed a nervous shock or a period of overwork, insomnia, anxiety or sorrow, and for them it will be easy to accept my diagnosis and my suggestion that they see first what the effects of reassurance and a rest will be; but others who have broken down nervously without obvious cause will be hard to convince. If to these persons I do not give plausible explanations for their symptoms, using simple speech and simple illustrations, and if I cannot patiently and convincingly answer all their objections, they will only move on to consult another physician.
ALVAREZ WC. NEW LIGHT ON THE MECHANISMS BY WHICH NERVOUSNESS CAUSES DISCOMFORTCLINICAL LECTURE AT NEW YORK SESSION. JAMA. 1940;115(12):1010–1013. doi:10.1001/jama.1940.72810380002010