I don't know that you can blame depression on ADHD itself.
My husband (age 60) was diagnosed as hyperactive way way back when and he's definitely ADHD. he drives me nuts, always dropping things, not finishing what he starts. He has a good job where he has to keep track of A LOT of details. It's very hard for him but he gets great reviews. he drinks a lot of coffee.
Bicycling makes his life manageable I think.