How to help a kid who is friendless and lonely?

(Throwaway for obvious reasons)Tl:dr - 15 yo son has no friends, is sad and lonely, need some advice on how to help himMy 15 year old son is finishing up his first year at an elite boarding school. He was so excited to get in, and happy to go - he’s bright and talented, and this meant opportunities he wouldn’t have had at home.The problem is that he is terribly, terribly lonely and has no friends. I had a heartbreaking conversation with him this week. They had a special day off, and I asked him what he did. He said he went to the local farmer’s market by himself and bought some bread. Because I monitor his social media account (which he - thank god - deleted from his phone and never looks at), I saw that pretty much the rest of campus had gone out in groups, or hung out in rooms together - it was a day of fun and relaxation and connection, and my kid was again left on the outside.I’m just so sad for him. He’s such a good kid - kind, funny, smart, handsome, athletic, musically talented, everything you could hope for - and he’s trying so hard to connect with people. He plays three sports, a musical instrument, is involved in clubs - he’s putting himself out there, and still has no friends. He has ADHD, and can be impulsive and socially awkward, but medication has helped a lot. He’s on full financial aid, but almost half of the kids on campus get aid, so I don’t think it’s the issue.He had a small group of friends (mostly couples) he was tagging along with, until the leader texted him and said they didn’t want to be friends with him anymore. He screenshotted it and sent it to me, and it was just gutting- basically the girl saying she thought he was okay, but no one else liked him, so he couldn’t hang out with them anymore. He spent his birthday alone in his room, and no one knew/noticed/remembered it was his birthday.He’s in counseling (depression), and he said he’s talked to his counselor about this, but the counselor just told him to keep trying.I just don’t know what to do. I really thought he would find at least a couple of good friends there - I went to a similar school, and the kids who weren’t “popular” still had their friend groups of other misfits/quirky/awkward kids. I also figured it would just be a matter of time before he found his people, but that’s clearly not the case. He insists he doesn’t want to go to school anywhere else, but I don’t see how being friendless for 4 years is going to be a good thing, no matter how good the school is.Has anyone else dealt with this? I’ve mostly just tried to be supportive and encouraging, and have spent a little time asking him to reflect on his behavior, and if there’s something he’s doing that’s causing this issue, but he said he doesn’t know - that people just don’t seem to want to get to know him, and the few that do know him don’t want to be good friends. As he said last night, “No one here cares about me.” I’ve asked his advisor, and she said the adults all really like him, but she can see that the kids don’t, and she doesn’t know why.I got him a couple of books on social skills, but I don’t know how helpful those will be. The basics - listen more, ask questions, be nice and friendly, etc - are things he does already.Any advice, or hopeful stories? via /r/Parenting http://bit.ly/2Lhxz1h