My Son Is Currently Being Treated For OCD And I

My son is currently being treated for OCD and I believe depression. He initiated a medical evaluation. He is 24, has a four year college degree, is in good physical health, is working but living at home. I've noticed odd arrangements in his room,,,,diagonals....repetitive patterns. For awhile, I noticed hair cutting behavior, but that has stopped and this new arranging behavior has started and is getting worse even with medication. He says his mood is better and feels better but other than that, things are worse. What should I as a parent do? I even tried changing an arrangement of shoes to see if he'd notice or care. No response. I'm baffled. He had used drugs in college for awhile, and we had him change schools. He did better but this is new. For a time, he obsessively played chess too. I thought there could be worse addictions than that but for the most part he isolates himself in his room and reads a lot. He does socialize a bit but not a lot. I've tried to encourage him to move and get his own place. He seems to be fine with that but hasn't acted. I'm not sure I should be doing that either given this. He also, btw, believes he has attention deficit, says he cannot concentrate and that's why he forces himself to read a lot. Please advise.