How would I know? Should I raise my concerns with her? She is mid 50s, single, no family, highly intelligent, well qualified, good job, but more and more often seems to be speaking total nonsense. She is insulting, paranoid or just totally illogical part of the time, then normal and intelligent part of the time. It is hard to give examples as I don't want to be specific, but she has been told she is in danger of losing her job, and her response was it is just jealousy because she is so beautiful. ( she isn't beautiful, just normal looking) She thinks these threats are because she doesn't want to sleep with the boss ( 20 years younger, and engaged - I very much doubt he has made any advances) She also beleives someone is following her around trying to steal her glasses, she keeps losing them. She is also forgetting to wash herselt or brush her hair. Then again she will suddenly be totally on the ball, and explain really complicated economic concepts to me clearly and lucidly. Then suddenly start telling me I am stupid for not knowing it already, or start explaining how many pence in a pound, as if she really thinks I don't know. What is going on?