So many others have hit the nail on the head in response to you, Sometimes psychotic.

I think having caring people around you is a huge advantage to recovery, in my experience, anyway. You spend less time being driven into your shell to avoid painful stigma from others. Having a sense of being loved and therefore being valued gives you something to counter the negative responses you get from other people.

The issue of social exclusion and social withdrawal is a bit of a circular one. I think we naturally withdraw from others when we have a psychotic episode, or if manic, cause people to be cautious of our overbearing and probably grossly self centred manners.
When depressed or suffering from trouble reading social cues, we feel inadequate, and also receive awkward feedback from others. That is often read by us as rejection when it is initially just people subconsciously responding to our lack of involvement. That then spirals into more defensive withdrawal from us, and then into a loss of social connections and lowered social appeal to others. etc.
It can be very difficult for us to break that cycle. For me, having people who understand what we are struggling with, and who actively assist us by including us in social situations has been a tremendous boost toward recovery.