It's simple... crazy does not get better with time. If your friends are telling you a chick is bad news... LISTEN TO THEM.
The SECOND you get a whiff that a chick is crazy... leave. If a woman ever gets to the point where things get so bad that you think you are about to lose your temper... leave.
Depp's problem here is that he tried to make something work that was NEVER going to work.
Don't try to 'help' her, don't think you can change her, making yourself miserable does not make someone happy.
When a chick loses her temper and and starts to rage against you, grab your keys... get in your car... and drive away... get a hotel room and figure out a time where you can go to the house and get your sh1t. This is where having female friends (or sister, cousin etc.) come in handy, bring them with you because you two are going to be fighting over stuff... understand that any 'stuff' you have isn't worth fighting over. Get out with as little cost as possible and be glad for your freedom.
We can all sit around and b1tch about how unfair things are... I suspect that Depp is really the victim here... but he never should have hung around this stupid situation. NOW THIS A A FACT: Your relationship chick can scream at you, throw things at you.... hitting you... she can even actually hit you. But if you hit back even ONE TIME, the court system will hold YOU accountable. Is it fair? NO IT ISN'T, but it is reality.
“He is free to evade reality, he is free to unfocus his mind and stumble blindly down any road he pleases, but not free to avoid the abyss he refuses to see.” ― Ayn Rand