Was originally diagnosed with depression and GAD when I was 15. Those symptoms resolved and didn't show back up until I was 19. I'm 21 now. You can say I've been 'ill' for 6 years, but I really think it's only fair to say 2. Because 2 years of illness is easier to overcome than 6.
My experience has been no where near as long as a struggle as others, but it doesn't change how it hurts in the moment.