How to talk to someone who might be suicidal

Take seriously all suicide threats and attempts. If somebody mentions suicide, even if it is just in a joking manner, it needs to be taken seriously. A common fear is that asking someone if they are suicidal will put the idea in their head. This is a myth, however. Instead, you are putting the issue out in the open, and you are providing them with the opportunity to discuss it with your support. Talking or asking about suicide won’t increase a person’s suicidal thoughts; it will tell you how strongly the person has thought about it. Talk to this person, and find out more about why he or she is feeling this way. If he or she is under 18, ask if you can tell a responsible adult, like a parent or a guidance counselor.

http://www.learnpsychology.org/suicide-depression-student-guidebook/