Look for one of your friends to be distancing themselves from the rest of the group. They are going through some of their own stuff right now, and the group dynamic is just not making them very comfortable. Let them know that you are there for them when and if they ever need you, and that you aren't upset that they've detached. Call them up, send them a text, or send an email that gives them a virtual hug, today. They will appreciate the gesture, even if they don't reply.