Most everyone in my life knows. I "feel them out" a bit before mentioning it. If I feel they will not be able to deal with it in a positive manner, I isolate myself from them until we "naturally" drift apart. That way there are no uncomfortable confrontations (yes, I have dealt with a few in the past n in my opinion they aren't worth it). For the ones I do tell, if they do not know what borderline personality disorder or depression or general anxiety or PTSD or psychotic symptoms are and what issues represent a need for concern, which ones are simply me misinterpreting, or how to deal with me should any of those things cause tension in our relationship (whatever kind it may be) - I answer any question and/or provide them with information. It keeps things running more easily for me.