There is something called hysterical conversion.
I am not a clinician but as far as I am aware it is is when getting upset results in physical symptoms, from little things like muscles tensing if someone is nasty to you, or having a vomiting feeling and wretching wind up if you have just had someone cold call at the door and then started shouting at you when you politely declined his offer to clear your roof gutters and you shut the window and felt, well, sickened and upset.
Has you friend had panic attacks, the first one "out of the blue" and later ones as a result of a slight trigger, such as bright lighting in a supermarket?
Sometimes the treatment favoured by clinicians is immersion in the problem, but in some people that makes it worse, it is better for them to be just signed off sick for a month, renewed for another month and they just potter around home and then sometimes the stress level decreases and they get better, as if the brain needs idle time so as to sort things out without needing to deal with further input.