My suggestion is therapy. Often times depression is confused w/ADHD - especially in boys!
I was going through a lot of the same stuff with my daughter (now 10) and getting her into therapy was essential to getting her back on track. We found that when we started, she was actually severly depressed (it's harder to tell in kids than adults - they may still seem happy, etc.) One thing I noticed you said was "grounding". We found, that taking away the few things that mattered was NOT helpful at all - it worked the opposite of what our intent was - and that was confirmed with her therapist. It was better to show tons of love and support, empathy for what she was going through (having seperated parents is hard and we have to acknowledge that). WE are the ones who chose our paths, not our children. Keeping her involved in sporting activites and spending extra time with her doing things that SHE liked (going to the park to shoot hoops, roller skating, day trip to NY, renting a fun movie on Friday nights and eating pizza inthe living room) made her feel important, that her ideas mattered and we did care about her and her feelings.
I have heard a lot of people say they can't afford counseling or therapy - but my response is that my daughter (and her sanity) is worth every penny of it. If finances are an issue, there are a lot of no cost/low cost options available - check out catholic charities (you don't have to be catholic to use their services) or other non-profit organizations too.
I definitely recommend this before you go the ADHD route. Most people see the difference with the med's mainly because they work quite like an antidepressant (which can certainly be avoided with talk therapy and love).