This is not correct. At least not in the U.S. as a whole.

It may of course be true where you are.

The DSM does not even suggest an IQ test as part of the diagnostic.

Knowing 6+ people in several states with ADHD diagnoses (some as children, some as adults) none have had anything beyond questions with their physician… or diagnoses by a psychiatrist after starting therapy for a different issue.

https://www.cdc.gov/ncbddd/adhd/diagnosis.html

https://www.ncbi.nlm.nih.gov/books/NBK519712/table/ch3.t3/

https://add.org/adhd-dsm-5-criteria/

I got diagnosed for ADHD in 2021 and nobody asked me to do an IQ test. In fact, no one has ever asked me to do one in my entire life.

Your anecdote is not data.

Also makes no sense whatsoever as ADHD does not affect IQ in any form. It's a form of dopamine dysregulation, not a learning disability. Let's stop perpetuating this stupid myth.

It does affect concentration and if an IQ test goes on for long enough and is not interesting enough to warrant some kind of hyperfocus, I get distracted. And so my IQ score will be worse. Or not? I have ADHD and it doesn't make me dumber, but since focus is a critical part of thinking, it does make it harder if I'm not interested. I'd rather say that IQ tests are designed for neurotypical people.

IQ is not concentration. In fact, IQ or intelligence in general does not have a single accepted definition†. You are not "stupider" because you have no patience to sit down to concentrate to do a silly test. Nor you are "smarter" because you found it so engaging you hyperfocused and did it in one sitting.

IQ tests are designed by people that want to create automatons easy to quantify and categorize.

† My definition of intelligence is "ability to solve novel problems." With this definition, an uncontacted tribesperson can be as intelligent as a Nobel prize winner. The difference is education, and the type of problems they're facing, which is just a matter of context.

I have ADHD and I do great on IQ tests, each question is a little thing to answer, I move quickly through them and get a quick dopamine hit. If there is something difficult then I can get stuck there and thrown off my rhythm, but this seldom happens.

Erh, where in the world?

Evidently I am an outlier? I was asked to do it twice as part of ADHD diagnosis.

Once in the UK as a pre/early teen (2003~), and once in Sweden to be rediagnosed via a private company named Modigo (so, now I am not sure if it's standard as part of the healthcare system here).

Since I was 2/2 and that was 100% of my experiences throughout two countries, I thought it was the standard.