Interesting, ChatNoir, thanks. That 'pep-pill' feeling is right -- I once took some diet pills (ECA stacks, bad idea, I don't recommend!) and this is sort of how they made me feel, like everything is 'revved up' -- interesting that you too are on an antidepressant, maybe this is the cause. I will definitely let you know if I figure this thing out, or how to deal with it effectively.

Sabrina: did this start happening coinciding with the use of antidepressants in your case? It happens for 'no reason' in my case too, or, no reason I can figure beyond it maybe being caused by my AD. It isn't constant, and strikes out of nowhere -- sometimes I just wake up that way.

MissBelle, yes, overstimulated! I don't drink coffee, but sometimes indulge in a good old diet coke -- particularly if I go to the cinema -- but I haven't actually found caffeine to make it worse (although I now avoid things like Redbull, just in case) Interesting that you too still get this feeling even with a beta blocker? I have found I get it much less often and much less severe, but taking a beta blocker hasn't stopped it altogether. I forgot to take my beta blocker the other day though and boy did I know about it!!

Thank you all for your responses, a great help! Sorry you're all suffering with it too, but at least I know that this thing could be what they say it is -- I wasn't sure! It still seems so bizarre to me that such physical symptoms could be down to what I'm told is 'anxiety'... Before this started happening to me I don't think I would have thought it possible. I'm hoping that the more I understand it, the better I'll get at dealing with it.