I'm the same... as soon as I feel a change starting, I'm apt to take that self-fulfilling prophecy route and pull out of the friendship to save myself the larger hurt. And, at least then I have good memories of the person left and only have myself to really blame. Whereas... if it goes to the point of them actually abandoning me, then it's like all the memories are tainted.

With friendships, I can go a long time between contact and still consider someone a friend. But, it depends on the dynamic of the friendship. Do they ever initiate the contact, or is it always me? When we talk, do they show an interest in my life, or I am simply inquiring about theirs and getting basic answers? If I come to visit their city or nearby, will they take any actual time to do something with me that isn't running chores with them? Do they only contact me if they need something? Once it gets to the point that the friendship is only there if I push for it... then it's no longer a friendship to me.