Meaning：
to be/become mentally confused or unable to act in a reasonable way

Examples：
be round the bend, go round the bend, something(someone) drive someone round the bend

Synonyms：
around the bend; crazy, flustered, frustrated, go mad, become mad

Sentences：
If I have any more problems on top of those I already have, I shall just go round.

I shall go round the bend with all this work

If I’d stayed there any longer I’d have gone round the bend.

Conversation 1
A: Where are my keys?
B: Didn’t you have them a minute ago?
A: Yeah, I don’t know where I put them, I swear I’m going round the bend!

Conversation 2
A: Are you still having problems at work?
B: Yes, my boss is an idiot.
A: How come?
B: He just seems to like driving me round the bend by making me do stupid things.

Conversation 3
A: What annoys you the most?
B: I’m not sure, I think when I have a fly in my room when I am trying to go to sleep, and the noise drives me round the bend.

(Callan book, Stage 7 649p）