I had to fill out a huge document (30 pages) going over my childhood and adult life, issues I face(d), and all kinds of other little things, as well as some multiple choice assesments. My mother had to fill out another set of documents (10 pages) about me. They required any and all report cards I had as a kid.

I had to get that all together and done before I went, because the clinic is a 2.5 hour drive meaning it wasn't practical to spend a ton of time there.

The actual clinic time consisted of an interview that took ~2 hours and seveal tests. The only test I remember clearly was something called the CPT test, because I thought what they were asking me to do was actually impossible (don't press the X when it's shown).

After that I had a follow up virtual call a few weeks later to discuss the results and they provided me with a document about all the testing, results, and steps going forward. In their own words I have "severe inattentive ADHD".

My main issue is if you know exactly what to tell them of course you'll be diagnosed, it's not like a physical issue that you can't fake. Someone seeking a diagnoses just for drugs could easily have gotten it. Additionally it was a private clinic and I worry there was some incentive for them to provide the result they thought the client wanted.