I have been diagnosed with SPD (among other things). I have one friend that I am really close to that I see at least once a week and often end up hanging out there longer than I planned. I have a few other friends, but I don't make it a point to see them. I don't have any psychosis, ideas of persecution etc. My diagnoses make sense to me. AvPD, DPD, SPD, DID, MDD.
Sometimes I want more friends and sometimes I don't. I think I read that SPD people are often quite lonely-they want friends but can't really make friends.