In the US diagnosis Is done by Neuropsychology usually but having the conversation with your doctors and other health professionals is a good place to start. OOP for adults can be rather cost prohibitive usually

I found a psychologist (not therapist or counselor) in a major city near me. They were able to diagnose me after about 6 months. It wasn't cheap (~$2000 w/o insurance) but I LOVED my psychiatrist and it was super helpful the way they explained things. They were really thorough and ruled out other things like ADD since that was also suspected. It gave me such piece of mind and led me to this app 🤗 I wish that psychiatrist was my regular therapist but I can't afford them :(