I only hope this is not to be the undoing of my commercial flying ambitions! Although the diagnosis has answered a great many questions regarding struggles in my life so far, had I looked into class 1 medical requirements in more detail I would have avoided getting diagnosed in the first place.
This is the important issue here. I'm concerned that your prescribing physician, as expert as he might be, did not think it wise to bring up the effect of medications on your eligibility to fly.
The FAA has a blanket prohibition for flying with ADHD medications. They recently established procedures to appeal the denial, but they are extremely onerous, costing many thousands, and amount to challenging the diagnosis. I would expect the CAA regulations to similar.
So the reason for my response is to point out to others, be they in FAA, CAA, or another jurisdiction:
Never, ever accept an ADHD diagnosis, or the medications therof, without considering the effect it might have on a current or future desire to fly.