Thank you for your query.
If I have understood correctly your friend has been diagnosed with ADHD
by one doctor who has been increasing the dose of Aderal without any improvement. I am not clear what the other doctors are saying both about the diagnosis and the medicine. Probably the diagnosis needs to be revisited and the medicine changed accordingly. As the symptoms and/or findings have not been mentioned I am unable to give any suggestions. It shall be better if you seek another opinion to confirm the illness.
I hope I have answered your query to your satisfaction.
Wishing your friend all the best.
Rajiv K Khandelwal