I'm not sure about the specifics, but it depends on the degree, as well as how and when you talk about it.
Talking to someone for the first time and going straight into "I want to kill myself" is... uncomfortable and tough to deal with. Or even if you know someone well-ish and it's all you talk about.
Honestly, I've had depression for years, and even my empathy has its limits when it comes to that. Why? It's extremely damaging to you as well. When I was going through a tough break up, I was "friends" with a guy who would constantly, endlessly, talk about how hard it was for him that his friend stopped talking to him after he had basically harassed her. Every day, for hours, not accepting any of my advice, and this went on for months. It drove me absolutely insane and I was already in a really tough position with my own life.
And finally, HOW you approach talking about it is a big deal. You're putting the responsibility of dealing with your issues on someone else. That's fine. You SHOULD reach out when you can. But you also have the responsibility of being empathetic towards them. Thank them for their advice, even if it doesn't help. Don't just go "That doesn't help man, you don't understand". Be calm and rational. Give them a chance to help and support you, rather than forcing them into it.
A little example. What do you think is harder to deal with
a) "I just wanna die man, help me! Everything is so ****** up, I have no hope!"
b) "Sorry man. I've just been going through a rough time lately. I've even been dealing with suicidal thoughts, and things just feel really bleak now. I appreciate you taking the time to help me out, you're a good friend"'
Obviously, A is harder to deal with. Just put yourself in the position of the person you're talking to.