Interesting, my future son in law was diagnosed last year at the age of 40! He has struggled over the years to deal with the way his head worked, or not at times, had difficulties with alcohol and he described it to me as trying to keep a lid on a boiling pot but having no control over the gas ring. Since last year and a minor tweak after a few months of the meds he was prescribed, he describes it as almost being like he has been completely rebooted mentally, he no longer suffers almost permanent insomnia, he has been able to engage fully with redeveloping his business and by his own admission he's a far easier person to be with than he was.
Well I want to applaud your bravery in posting this and also congratulate you on turning your life around. Take credit for what you did to make a change. Over here in North America (Canada) ADHD is definitely over diagnosed in children I'm not suggesting that's a good or bad thing. They push pharmaceuticals over here so much its hard to know who to trust but I am sure there are many cases like yours that are a good news story where medication really turned things around.
