How do clinicians usually decide whether a symptom is medication-related or just part of daily life with ADHD?

That's a difficult one! and depends on the symptom. so for me, i would consider if the symptom existed before medication or not, if it was before its perhaps not medication related. I would ask your opinion, the expert of you is you and so i would ask what you think it is and more importantly what you want to do about the symptom. Id ask if it causes you distress, if it does then lets look closer. In some circumstances I might reccomend we adjust dose to see if the symptom goes away or gets worse . I might also reccomend psychological work , depending on the symptom. We do an extensive amount of training, but we dont always know the answer If we got stuck we would ask our collegues.