I think caffeine can be as problematic as any other substance for some of us. I stopped it cold turkey almost 10 years ago because I was using it to get manic and it worked quite well for that for me in large enough quantities. Eventually I had to admit (I think my pdoc asked me how much I was consuming) that I was way overdoing it and causing bad problems and ruining my job and life. So I stopped. Monster headaches for a bit and then a reminder that I might need APs (as I did then) but APs tend to hate me and so I was very hard to stabilize after I did such a good job de-stabilizing myself with the caffeine.

I'm sure it's not true for everyone but it can be.