Should I tell people about my mental disorders?

I have tried several approaches to this myself and I thought I might share them.
Firstly, diagnoses are highly subjective to the doctor, to symptoms at the time, to the current way the DSM is shaping up (bloody thing). There are some which do not fit with me at all and therefore I do not feel any need to use them, and others which are not 'officially' proscribed by a Doctor but which I feel fit and my therapist has agreed with, which I therefore have used.

A long while ago after coming out of IP (in-patient) I was very open about my mental health issues, and to be honest this was a mistake. I didn't particularly get abuse, I was at school so people who didn't understand just didn't. But it meant that I used these conditions as a barrier to stop having to connect with people and to work on trust issues. Also I have had a scenario where I was friends with someone, or so I thought, but after a few years I realised I was nothing more than some 'interesting freak' to her and therefore stopped contact.

Equally I have pulled back and not told people things, but this has been problematic. It means people won't understand if there are issues at any point; I mean perhaps they wouldn't understand anyway, but they would at least have a sense of explanation for behaviour or absences. I have found this only causes issues at work, in education or at home.

Currently, I tell people I have 'been ill' (I have also had physical problems, some related to mental health and others not) because it explains gaps in where I was. People are often curious but I hold back on specifics and make generalised comments to them. When you have started to connect with someone personally, then you can begin to mention issues as and when you feel appropriate, for example explaining about social anxiety can be helpful early on because it prevents awkward social expectations of what you may or may not enjoy. But equally stressing that friends shouldn't treat you differently, ie. in asking you to things, with this understanding means you could constantly decline if you had such an issue and it prevented certain situations.

Equally it is ok to tell people where you do have to be treated differently. Where very ignorant comments will be triggering, although hopefully out and out prejudice will not be a quality your 'friends' have. I had to be very very specific about some triggers in the summer because I was totally destroyed into relapse by some comments and treatment by someone. It is, unfortunately, something you have to repeat with some people because luckily for them they don't get it. Although they should make an effort to understand, sometimes the privilege of their mental world prevents that from being possible.

All in all I think it is worth flagging up especially with official channels such as work or education or anything like that. It provides cover for issues.

With new people a little information can be good and can help oil the wheels of empathy between you. But even if you feel a close connection an all out confession probably won't help. I find that then constructs friendship based on understanding of mental issues rather than a strong foundation of mutual liking- a recipe for future falling out/triggering.
With current friends it may seem difficult to bring up, and ultimately you must decide if they are properly friends in which case it will help them and you for them to know triggers or when you might not feel your best.

Revealing nothing puts you under constant pressure to hide, conceals a very real part of you from people and potentially puts you in harmful triggering scenarios. I have generally found people are not abusive, if anything they are over-enthusiastically curious like seeing a brightly coloured bird. I know someone who is an amputee, and I can relate to that sense of children looking at you because they wonder why not because they are disgusted; I think people are generally very interested rather than repulsed. Lots of people are open about mental issues now, I know certainly they were when I was at school and in work.

Hope some part of that helps.