Yea thats a great way to prevent people from commiting suicide, tell them theyre stupid and weak >.> really, this is a sensitive subject try to be a little nicer.
while thats not the way to help somone open up to you, a fresh dose of reality can help a person whose being depressed, and overthinking things. Like a slap in the face. Its not a common way of pulling someone out of a serious ailment, but it can work