I have the feeling that helping friends out might be a more difficult problem them helping family members. Family members are your blood and flesh, they have been around for as long as you can remember. You can be relentless, you can tell them they owe it to you and to their family, you can build your plead on years of knowledge of this person and you are close to the rest of the family, making it easy to coordinate efforts and make sure that these efforts are varied, so that the person doesn't feel like running away from everybody completely. With friends, I always have the feeling I have to be more tentative. Push as much as the relationship allows it, try to vary my points and inspirations by myself. I'm also never sure what might have a chance to "get to them", having many times not this many years of experiences to rely on. When did your friends dropped their guard down and let you in? What is it you told them that made them understand they needed help? Is there a basic argument/expression of care you use that has the power to get through to people, no matter how close you are to them?