Self-diagnosis is a valid thing, especially for adults, people of color, and people who are AFAB. Both ADHD and Autism are primarily researched in adolescent white boys, so how these diseases present in other populations is not as well known. Don’t sweat it if you don’t have a slip of paper from a doctor.
Edit to add: there’s also the component of privilege. Not everyone can afford to go to a psychiatrist to get diagnosed.
They should make the government super efficient and fire themselves