Hyper focus is an explicit trait of adhd where they have very intense focus on one single topic.

Also consider

• Being overly stimulated
• being socially clueless/akward
• having niche special interests
• more often have an interest in computers and gaming
• can be very good at theatre/pretend from a lifetime of masking
• gets shunned for being weird (becoming the class clown is an adhd strategy to avoid this)

Combination of both diagnosis is not uncommon and there is even a pattern where high level at functional masking autistic people get an adhd diagnosis in school long before autism is “discovered” in adulthood.

It has heen proposed that adhd, just like some other neurodivergences (ocd, dyslexia,..) should technically all belong on the autism spectrum, they are all about “the brains network of neurons being build in a non typical way”, which is also why everyone is still unique, but doing so would make it harder to medically label the specific needs of the more challenging forms of autism that need that label to get appropriate help.