ADHD is so poorly defined and with such terrible standards of evidence for a valid 'theory' with an incredibly wide source of potentional causes of ADHD thought

ADHD is so poorly defined and with such terrible standards of evidence for a valid 'theory' with an incredibly wide source of potentional causes of ADHD thoughtout one's lifetime, that I question if any correlation tied to the concept of ADHD means anything at all. The amount of money and researches dumped into dopamine transporter studies, brain diffusion tensor image scanning, the outspoken desire to test the pre-frontal cortex of monkeys, because lab mice don't have them and they still don't have any quality evidence to identify adhd. Enron has a better return on investment for shareholders than ADHD clients have for research dollars.