Unfortunately, around here where I reside (and else where), there are very few places to turn to get the proper PROFESSIONAL help that one needs.
Most of the time people can't tell when someone is "going off the deep end".
I had a friend a couple years ago who attended my aunt's bday party. He seemed fine, looked fine, sounded find, but was not fine, because the next day he committed suicide.
And speaking personally, I have suffered from manic depressive for years...I didn't tell anyone up until this year about my thoughts of suicide. A lot of people won't come right out and say it because of fear of judgement, fear of people not really taking them seriously.
And it is often when people hear of someone talking about, suicide and even homicide that most people think that they are just joking, or are in denial about what they hear.
Most of the time when someone speaks this way, they are crying out for help before it's all too late.
I think the best response is to take time and listen, don't bombard the person with your personal views. Because for the most part they just want to be heard.
Once you do listen to them, seek out whatever professional help you can get ASAP...A lot of states have private funding for mental health and will work with people from low-income on a sliding scale.
A lot of churches offer counseling, non-profit organizations do as well...And I know that those who are active or veterans, that the military has special funding for that as well.