The BBC Radio 4 programme 'Inside Health' had an item on this last night. It is repeated today and can be downloaded - at least in the UK. I think the item was near the end. There are some good links on the programme page: http://www.bbc.co.uk/programmes/b01rr37c At least one linked page includes reference to diabetes insipidus, saying that it usually improves. So much for my 'top endocrinologist' who swore that you had to be born with DI to have it, and that it was an all-or-nothing condition (no variability, no possibility of it being partial). Even I knew from a little research that that was wrong. I suffered brief concussion in the early 80s following a fall, and have often wondered whether that contributed to some of my later problems. I don't recall any health problems starting around that time, but effects can be delayed. A significant effect of minor brain injury is chronic adrenal insufficiency. One linked page includes a complaint about the major UK health service body NICE neglecting hypopituitarism. Sound familiar...?