The common refrain from cognitive therapy is "negative thoughts cause depression." It's based on this model:

And this is what cognitive therapy targets:

But that's a causal fallacy. If there's something really negative in your life, like an abusive relationship, no amount of dispution is going to make you all-of-a-sudden feel comfortable with the negative external events.

I believe that healthy individuals with high EQs focus on all four parts of experience. If they're feeling blue, they try a pick-me-up, like playing sports. If they're having overly negative thoughts, they have a voice in their mind that is skeptical. If they're perceiving an injustice of some sort, they seek more evidence or get some distance to balance their perspective. And if there's truly negative events, they change their reality accordingly.