I filed for SSI disability several years ago and received it. At the time I didn't know what was wrong with me. I have found out recently that I have lyme disease and the doctor thinks I have had it since I was in 8th grade. That would be over forty years.
At the time I filed for SSID I didn't have enough credits for regular SSD and I still do not have enough.
My question is since I got sick when I was so young can I go back and file again for SSD since you don't need as many credits when you are younger?

A couple of things: You were awarded SSI Disability and have been collecting the payments for some time now. You're receiving the same amount (basically - a couple of 'what ifs' can come into play here) as everyone else receiving SSI. There's no way SSA is going to suddenly re-open / review your entire case and give you retro pay for 40 years. And the fact that your doctor "thinks" you might have had it for a long time is Never going to fly. Your 'claim' was received and approved, be happy with that! I just heard there are apprx. 500,000 'claims' waiting to be processed...

You may, however be eligible for CIB ( child's insurance benefits) if one of your parents was recing disability before you turned 22 and can prove it.

NO
They never go back further than the date you applied.