Knowing which friends will be there for you when times get rough separates your true friends from acquaintances who are friendly, but really only want to support you when things are going well. So, how can you tell which friends are which ahead of time? And is there any way to fast track strengthening a relationship without having to go through a traumatic / stressful / unpleasant experience?
You need to make yourself vulnerable. It demonstrates that you are willing to trust your friends and it gives them a chance to rise to the occasion. In an extreme case, one study found that you can fall in love with anyone if you take time to ask and answer 36 questions that are increasingly probing. All of this is to say, you need to make a conscious effort to let your friends in.