Spike - Poly party, because he genuinely doesn't know how to deal with it. He'll also drop by murderous anonymous in memory of better times with Tyki because he feels like he should, probably. It's good for the soul.
Reid - Abandonment issues, addicts anonymous.
Wade - All of them? Uuuuh murderers anonymous, PTSD and you, terminal illness, maybe something else if I can think of it. You bet he'll drop by the poly group just for shits and giggles and stale donuts.
Aidan - PTSD, impostor maybe?
Chuck - she's doing so frickin' well I think she'll sit this one out and just make post-therapy treats for people who might need an extra dose of chocolate today.