Thank you for bringing some light into this cavern of ignorance.
On the 'reality' of mental illnesses, if I can be a little less serious, I do still recognise (as did my favourite professor) that it is still a very odd position to be in, to say that the illness must exist because of the presence of the treatment. Suppose that the treatment had for some reason not been invented, does that mean the illness didn't? Did the illness become 'real' the moment the treatment was discovered to be effective?