We had no clue it was ADHD. Ds1 had always been difficult (horrific sleeper, highly emotional, hyper sensitive, very demanding, very active, difficult eater, utterly wonderful but exhausting). Id done online autism questionnaires but nothing was flagged.
He used to get awful, regular migraines. I spent so much time seeing various specialists to see if we could find out why. Eventually when he was 8 I got his eyes tested again. Perfect eyesight but weak muscles so sent for "physio" for eyes. That physio literally changed our lives. The lady said she thinks he's dyspraxic and put us in contact with a pedopsychiatrist (we re not in the UK). He got tested and came back with a diagnosis for dyspraxia but she said there were also signs of ADHD so sent him to be tested for that. Diagnosed age 9.
A year later after much research into ADHD I said that DS2 shows even more signs of it than DS1 (especially hyperactivity) so I got him tested. And he came back with the same 2 diagnosis, despite them both being very different.
Ways we changed our behaviour: basically I realised with horror that we spent loads of time criticising DS1. How he held his cutlery, couldn't tie shoe laces, rolled around on the floor whilst reciting his lessons instead of standing neatly as he would have to in school. His handwriting. Any bad marks at school. His emotional outbursts earnt him time out in his room. Except he hated it so we would carry him in screaming 😥. Lots of little things which the diagnosis showed us werent his fault.
He also strongly reacts to my emotions. So my stress and unhappiness set him off.
We decided to step back on all the little niggles that actually don't matter. When he got angry and upset, rather than tell him off I would just hug him. Or just sit there waiting until he ran out of steam at which point he would come for a hug. He used to drive me crazy by not talking properly but just come into the kitchen and groan at me. I'd snap and it would escalate. Eventually I started saying "use words" and so he told me he wanted a cuddle. So simple!
I can't remember many other things really (it was a very tough time) but the main thing was we took a HUGE step back and started looking at it that DS1 wasn't responsible for his reactions and behaviour. So we relaxed, and relaxed the punishments. And his behaviour improved enormously. The ADHD meds stopped his migraines and help him regulate his emotions. We still have some bad days but I've stopped telling him he's wrong for what he's feeling (even me simply saying that XYZ don't matter wouls set him off because to him they DID matter).