Hi,
FIrst, let me say that you have a beautiful site! It looks very professional and well put together. You've done a fantastic job!
I do want to suggest a couple of things, though.... you might want a couple more forums, just to even things out, but not *too* many. With a small user database right now, lots of forums without a lot of posts will overwhelm newcomers and registered members alike! However, just to round things out, you might want to encompass a few more popular disorders: I would suggest forums for dissociative disorders, personality disorders, and possibly something to include learning and/or developmental disorders (autism, asperger's, dyslexia, etc.). You might even be able to drop whichever disorders you choose from the latter category and combine them with ADD/ADHD, since they are often grouped together.
I think the size of the forums right now are excellent, but just wanted to throw out a few more ideas. Keep up the good work! On a side note, I've moderated, admined, and created several message boards (my primary one is for dissociative disorders-- feel free to take a look at it). If you need any help, technical or otherwise, feel free to drop me an email. :-)