What I find frustrating is discussing with doctors that not all focusing difficulties are caused by depression. I do experience periods of (unipolar) depression.
One thing that I notice among "smart" people is that its easy to burn-out.
My only real advice is aim to do things that your passionate about. Two examples that come to mind is Elon Musk[1][2], who clearly enjoys building rockets and electric cards, and Mitch Altman[3] who enjoys making cool things. Elon Musk hasn't commented publicly on ADHD specifically. Mitch is well known for his public discussions on depression.
[1] http://en.wikipedia.org/wiki/Elon_Musk
[2] http://www.forbes.com/sites/drewhansen/2012/05/24/elon-musk-...