[ElProximo]

Originally Posted by Late for the Party

When someone can show me any case, where, under reasonable scientific conditions, it has been proven, that someone who believes something so much, become physically disabled, completely incoherent, I will then take back everything I have ever said about Dave.

Trying to add a bunch of talk of 'scientific proof' is lame because you can dismiss anything except maybe maths,
however,
If you need to know then you might look no further than Derren Brown although others have worked with this too.
You bet.. yes indeed people can work themselves into euphoric ecstatic states through self-induced psychosomatic states.

You may have also seen (in life or on television) where someone in massive mental/emotional distress has lost their ability to stand.
Upon news the husband has died the woman becomes hysterical and seconds later her legs give out.. relatives must hold her up.

I was reading about a thing in wars 'shell shock' where men.. due to psychological trauma had become paralyzed.
There was no actual physical damage to their legs but traumatic fear etc.. they were literally 'scared stiff' and unable to walk or move.

Not exactly the same thing but here Brown shows how people can be convince they are drunk and their bodies will act accordingly:

Youtube video