It depends on the medical professional involved in the process. No matter what test they may or may not use, at the end of the day diagnosis is always up to the subjective opinion of the provider.
This was my process that started at age 28 while I was in graduate school. (I’m 30 now)
It started with a friend getting diagnosed. Talking to her about her symptoms, I kinda just thought all that was just normal existence. It then lead me to suspect that maybe my struggles weren’t exactly “normal”. So I dug into it and starting learning about ADHD through various online resources. Eventually became entirely convinced and self-diagnosed. I so cleanly fit the pattern ever since early childhood and while I had developed some decent coping strategies, things were always on the verge or in the process of falling apart.
I started with Cerebral which has the well-earned reputation of being a pill-mill company. I didn’t even finish explaining my symtomology and background before the prescribing NP said “sounds like ADHD, here’s an Adderall prescription”. It took like 30 minutes.
Adderall was life-changing and helped a ton, but after a while I started getting some weird emails from people not associated with the “treatment team” at Cerebral asking me to make an appointment with a doctor to get drug tested. This was because they were getting heat from the DEA. I saw the writing on the wall and decided that the best move would be to find a new provider that was local to me.
So I got an appointment with a local place that mentioned Adult-ADHD. The process with them was supposed to consist of 2 separate 2 hour screenings. In the first meeting with them, I answered questions and explained my personal and family history, symptomology, and what medication treatment had been doing for me. That meeting ended up only lasting an hour, the Doctor thought my analysis of things was legit and she offered to continue treatment without needing the other 2 hour followup. I’ve been seeing that provider ever since and she’s been great, eventually switched to vyvanse.
So yeah, I basically self-diagnosed, got treatment through a pill-mill. Jumped ship when it seemed like the company was going down, switched to a legit provider and used the effectiveness of previous treatment as a solid piece of evidence for why it should continue. No weird test needed.