Depersonalization/Derealization Disorder
The distinguishing characteristic of depersonalization disorder is the feeling that one is disconnected or unreal. Mind or body may be perceived as unattached, seen from a distance, existing in a dream, or mechanical.

This is awkward.
It sounds as though this description is almost written about me.. but only sometimes?
It occurs when i'm in a particularly down, manic or angry mood. It's like I'm seeing everything through a net curtain, like i'm not really there. I hear everything going on, but it doesn't register as such. It's impossible to focus on what's being said.
But how do you tell if it's derealization or just lack of concentration? Because think about it, when you can't concentrate, you don't feel as if you're actually THERE. you're sort of wrapped up in your own thoughts. i suppose it's slightly different, but i don't know what to think.
Are my concerns a bit far-fetched?
They are aren't they.

Any thoughts?