WI was informally diagnosed when I was 16, shortly after I had my first nervous breakdown.

Know where being diagnosed young got me?

Dropped out of high school and am now working a dead end job I hate and considering the merits of getting myself committed just for the holiday.

Personally I would have appreciated the chance to establish myself before becoming a complete nervous wreck.

Although I have noticed those diagnosed later in life do seem to take it a little harder. Even though they may be in a excellent job with a loving family for some reason once they are diagnosed nothing else seems to matter. (Which I think may be in part because we don't come to the attention of MH professionals until in crisis.)

I don't think it's age that matters (although perhaps it is easier if one is less set in their ways) but access to resources. (And lets face it, most 20 somethings do not have the earning power or savings to afford such resources.)