My 30 year old step son has had substance abouse issues since 14. He says he's been clean for long time, but last night he came over and seemed to be acting irrational. He's been eating a lot of candy, he's very thin - but eats non stop. Last night he was folding laundry and took every piece of clothing to the light and inspected it thoroughly for spots. Then at the dinner table was obsessed with trying to rub off spots on his shoes. He also couldn't sit still. Are these signs of using?