Personally, the first step is identifying it. I have to see that I'm spiraling downward. Once I've recognized the negative thinking patterns and such, then I have to get help. I can't pull myself out of that spiral on my own (and at the end of that spiral it gets really, really bad). So I email my counselor or call emergency services here or something like that. Basically I need someone to talk me back up so I can get my thought patterns broken and correct my actions.