I don't think it matters coz it all happens so quick, what is more important is which happens last - how to stop it....
Still... sometimes bad thoughts or bad situations set me off, othertimes my moods are crazy without the thoughts, I think part of the Bipolar chemistry mess up makes our feelings messed up even if our thoughts are ok.....
How to stop it - bit of both - meds for the feelings and CBT for the thoughts....