Someone could certainly be a billionaire and also have ADHD.
The criteria is more like “but for this tendency, the patient would be/feel better, all else being equal.” A software engineer making $$$ could meet the criteria if their inability to focus keeps costing them promotions, launch their own company, or whatever their goal might be. A neurotypical buggy whip maker who can’t find or hold a job doesn’t qualify, even if he is obviously worse off overall.
The criteria is more like “but for this tendency, the patient would be/feel better, all else being equal.” A software engineer making $$$ could meet the criteria if their inability to focus keeps costing them promotions, launch their own company, or whatever their goal might be. A neurotypical buggy whip maker who can’t find or hold a job doesn’t qualify, even if he is obviously worse off overall.