Yes really. It largely depends on the place, but I can absolutely positively confirm this is how many of them operate. Not just with ADHD either. I've known people with TBI whose TBI is treated as bipolar on the sole basis that people hear bipolar and think mood swings. There's one person I know who was put on two lithiums a day for it and then yanked off of it and had to endure a whole month of hallucinations, only to be put on half of the original lithium dose again, all because they didn't properly insert TBI into the diagnostic list and thereupon this one psychiatrist just assumed it was bipolar (when there are differences in how mood swings from both manifest; TBI is rapid fire and bipolar is more like a long storm).

Every time I mention psychiatrists on this website, I get hated on, but I know my experience and the things I say are not going away. They and counselors DO overstep, they DO take on each others' roles and functions, and they DO conflict with each other at times. Glad to know though the same people here who say the US health system is shit also claim the psychiatry system is somehow a perfect well-oiled machine, free from people acting outside of their jurisdictions.