[speeddemon]

If he's becoming too much of a nuisance gradually break contact. Given that he's apparently unstable on the side of a depression, a sudden break from someone he considers a good friend might be too much. I've been a suicide hotline for some people for extended periods of time, and if you start ignoring unimportant things eventually they stop coming to you with their problems, and at that point you can either warily bring yourself back into friendship with said person, making it clear you have no intention of helping them through any bullshit unless they actually need the help, or you can break off all contact knowing that you caused little to no damage.