M.S.
I have 3 total (1 that is now grown, 1 that is 19 yrs and 1 that is 14 yrs) with ADHD, impulsivness and yes at times depression. The depression is normal for kids with ADHD as is the impulsivness. It depends on the age also as teens usually go through mood swings as it is and when you add ADHD it intensifies the emotion. The 19 yr was so bad when he was 14 that the doctor diagnosed him as bipolar. He was put on mood stablizers for 3 yrs only to find out that it was not bipolar at all but was a moody teenager with adhd. Right now we are dealing with disorganization that is part of ADHD and how to resolve that before it becomes more of a problem. After 19 it ususally becomes less of a problem or something that can be controlled on their own (or by that age they should have tricks and skills to manage it).
If you have any more questions about dealing with kids 11-19 yrs with adhd just ask and I will try my best to help.