There are many genetic and environmental causes to ADHD though, so I am in no way saying that a B6 issue is a cure all. But if you have high Homocysteine it could be a sign you need B6.
In my case it's genetic. My mom & sister also have it. My grandmother has Parkinson's, so I'm extremely likely to also get it at some point. I've tried all recommended vitamins, supplements, etc. nothing really helped as much as Concerta.
You should get a full genome run on yourself and whoever else is affected and start investigating if you have polymorphisms in some of the genes responsible fro making dopamine or issues with antioxidant enzymes like GPX:
It's fun to find grey/read links at random in these threads. B6 worked for me and adding B2 was also beneficial. But make sure to read about B6 toxicity as well. And you're going to freak out your doctor if you tell them.
By taking B6 in the form of P5P you reduce the need to push the Pyridoxal Kinase enzyme (which uses zinc) and you will more than likely not have any neurological side effects. And you will also save your ATP for better things.