Another possibility is co-existing autism. For years after the ADHD diagnosis and decent medication help, counselors and behavioral MD kept suggesting a mood disorder was also at play. I just didn’t see it. Outbursts were situational, not consistent. Finally, at age 10, we started seeing some possible symptoms of autism and he was diagnosed with that in addition to ADHD at age 12. The autism traits explained the outbursts (and other things) completely.
Penny
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism