Dizzy
Unfortunately, when you need to inform the DWP of a change of circumstances and when you don't are seperated by a whole area of grey.
As you are in the WRAG, they key question to ask yourself is whether this new conditon would entitle you to be placed in the Support Group? If you believe this to be the case, then you should notify the DWP, if not, then it really boils down to how significant the new condition is, which I realise doesn't really answer your question
Gordon