Seriously what is the deal with Kristina?

What in the heck is Kristina's problem. She is always attacking Sonny every chance she gets and now she is attacking Alexis. I guess therapy is  so not working. And don't blame it on her being a teenager.  I wonder how far she would get with out any help from Alexis or Sonny. Even though Nickolas would help her but still. Kristina is a little stuck up brat and people can't blame the whole thing on sonny. And yes Johnny is the blame for for some of this too. People say Johnny is no different from Sonny. Hell he is no different from Anthony either. AZ would do anything to crush anyone. But Kristina needs a reality check real quick. And if i hear her mouthed off to one of her parents one more time and neither one of them do anything to her i am going to have a fit.  Could kristina be bipolar as well?