This should also be added to ADHD/ADD symptoms: bipolar illness. I know adults & children with both. Kids that are diagnosed incorrectly as ADHD & later to be found to have bipolar. Bipolar can mimick many illnesses.
I have researched bipolar extensively & belong to a support group. I have bipolar type 2 (treated).
It took over 20 years of me being misdiagnosed with unipolar depression only. As I got older, the depressive episodes became longer & deeper. I used to have hypomanic episodes that caused a lot of problems in my life. I wish I could've been diagnosed sooner!!
I hope this helps someone else.