I have a friend who is clinically depressed and cuts himself severely (the worst I've ever seen, honestly; his arms are covered with scars), and is also into Bdsm and is turned on by the idea of having someone else cut him. He says that for him, the two are completely unrelated -- he doesn't feel excited by cutting himself, he just does it to lessen the pain of depression. For him, as for a few other cutters I've known, the big problem is that after the endorphin high from cutting wears off, he feels ashamed of himself for doing it, which makes him more depressed, which makes him cut more, etc.

I don't think that the masochism involved in BDSM is like that. While someone involved in consensual sadomasochistic activities does receive the same endorphin high, I've never heard anyone talk about feeling bad afterward -- certainly most of the masochistic posters on this board seem to be comfortable with themselves and the activities that they enjoy.

I guess that was a long way of saying that for me, the difference between healthy masochism and unhealthy self-destruction is the effect more than the motivation. If something you do makes your life worse, not better (my habit of staying up really late posting on the internet, for example), then it is self-destructive. If you enjoy being cut because you are excited by the sight of blood, and doing it makes you feel good about yourself and your relationships, I don't think that that's self-destructive.

It's sort of like the difference between someone being overweight and happy that way, or someone being overweight because they can't break out of a cycle of eating and feeling guilty about it and eating more (not that I've ever done that or anything... ). It might look the same from the outside, but one person is in control of their life and one is not.