As an ADD adult, I can say that I have had obsessive interests my whole life. They will change based on whatever is happening in my life at the time and they can evolve as I learn more/obsessively research whatever topic I’m into at the time. The downfall of my ADD brain is that I’m only able to hold on to all info for a little while and as my interest fades so does my knowledge. I will also completely ignore everything else around me while I’m engrossed in my project or research. No dinner, no laundry, late to pick kids up at school… oy vey.
My ADD son has had one true obsession in his life, starting before he could walk or talk, and that is CARS. Anything and everything cars. He’s now 14 and knows so much about cars that it’s difficult to drive down the street with him without getting an earful of facts. His other obsessions have included sharks, Star Wars and certain video games, but he’s a dedicated car guy and that’s how I got him to start reading. Since he’s also dyslexic, he never cared to pick up a book so I would get him fact books with pictures and tidbits of info on each page. It worked for him, as it was not too much reading, which would have turned him off.
If your child has obsessive interests, they should be supported. They are our passions in life.