Medication for psychological issues often have severe side effects. It is understandable to not want them if the issues are manageable.

The Physician is Always Right! TM

More like "the physician probably knows more than the 14 year old."

The doctor will know more, but they spend far less focus on it. They are also biased to over prescribe medication (at least in the US) to an extreme extent. The bias alone is reason to second guess all judgments. (Really, go look into the over-medication of young children with off label prescriptions. And part of the issue is that it isn't just the doctor pushing for it, often the parents want a cure all pill as well.)

Depending on the age of the poster the old way of treating an ADHD diagnosis was to slow the brain down. I've had friends that went from jumping off tables to being on cruise control once the meds kicked in.