Having ADHD didn't stop Scott Kelly becoming an astronaut and making four flights, prior to that he was a US Navy pilot flying F-14's and a test pilot, he says he got into the system before ADHD was "invented".
Why is Avmed even needed to give you a tick, they have laid down the requirements and surely your DAME can see if you pass or not. CASA delegates the responsibility for your checkrides, why not medicals?