The doctor on YouTube channel HealthyGamerGG has a lot of good information and has recently written a book for parents.https://www.healthygamer.gg/how-to-raise-a-healthy-gamer
As a person who knew I had ADHD (inattentive) since middle school but didn't get an official diagnosis and treatment until my late 30s, I would recommend exploring an official diagnosis and treatment. 2 reasons: 1) It might take you years to get a diagnosis and find an appropriate therapist. 2) I now look back and wonder if I could have done better in my life if I got treatment sooner.