It can stir up with me, usually it is a response to a trigger and that's when it's really hard for me. I don't intend on hurting myself either, but this symptom does occur. I know thoughts or impulses are separate from my choosing.
At the very worst I have been literally immobilized, unable to move, just at a complete standstill, a stand-off almost. I understand in myself, this is some sort of habit that is totally connected to childhood, I remember when I first started having this. I remember really badly, just wanting to disappear.
It was a way I had to annihilate my feelings, it's been a bit hard-wired into my brain to have this reaction. I've read from this article called The Internal Family Systems Model, by Schwartz I think is the author-- it's on-line in any case, but I think this suicidal part of mine, functions as a "firefighter" it helps cool out the fires, to protect me from becoming too overwhelmed. I've been doing better by allowing myself more, taking on an attitude of acceptance for what comes up. I've been finding other ways to process my feelings safely, write to externalize them, or draw or whatever.
My brother had a persistent 'voice' bothering him with these 'commands', it looked like schizophrenia in that way, but it never progressed and it went away. It's changed a lot now. I think my brother probably developed a bit of Dissociative Identity Disorder and the help here is hard to get, but we learnt creative ways for safe expression. He'd tell me stuff, and I'd draw it or paint it to see if that helped him-- and it did, which was really cool. He had a very elaborate mental construct he created as a child to help cope and help contain-- we've gotten to know it, and it no longer carries the intensity for him. He's learnt really well about how to work with himself, keep detached from these things of mind. It was just simple love and respect my brother and I have for each other. It was like an OCD, on the obsessive side, that's also a normal childhood response to a severe trauma. All I can say is after 10 years of this craziness both my brother and I have gone though, the clouds have been lifting significantly. My brother is brilliant in the way he's been able to adapt-- he's thriving now and I'm really really proud of him, and because I really appreciate the struggle he's been through. Crappy home-life, but the blessing of a truly awesome little brother!