If your girl is mercurial as hell and always having drama whose resolution never seems to stick, that’s more likely BPD. Now if your girl is normal or even a little sad most of the time but then suddenly comes to you with a plan to kill her grad school advisor and parents and live in their vacation house back in 1998 for the rest of your lives, that’s bipolar
The ironic thing about this whole episode is Felicia Sonmez going on absolute fucking tilt makes more sense if you assume she’s manic right now