Doing this can be a sign of mental illness - i.e. adopting different personalities to cope with her problems. Given that she's only just started doing this, while doing all the other crazy things she's been seen doing lately, I'm not sure anyone but a professional could say if it's related or not.
I have heard of multiple personality disorder, and what she is going through now might be a catalyst for that, but if she really was having British and Spanish personalities wouldn't the accents be better than that?
Maybe she just picked it up from her new pap-boyfriend? Aside from whatever other mental problems Britney may or may not have, it is entirely possible to pick up accents from those around us.
Yes, but I'm around DB quite often and I have picked up a few things, and sometimes end up saying both ways at the same time, but not a complete British accent, and hers doesn't even sound right. It sounds fake.
If she's manic, which she probably is because they said she hadn't slept in 96 hours or something like that, it could be part of that...I don't know much about bipolar though, so I'm just guessing.