Well, the title's pretty self-explanatory I guess.
If you have any kind of anxiety disorder, like social anxiety disorder, panic attacks, OCD or anything similar feel free to join, even if you don't have any actual disorder but you're still incredibly shy.
I started this group not only because I have both OCD and social anxiety disorder (no wonder its acronym is "SAD"...), but especially because I couldn't find any group for people like us, even though I found a fair number of users who aren't afraid to admit they have this kind of problems.

Well, I conclude the description with a very sweet song by The Smiths which is likely about shyness: