i think your sentence may be missing a word. is it "the correct WAY to find out". make an appointment with his doctor.take him in and tell his doctor that you need a referral from him to a doctor that can test himn for adhd. a behavioral doctor a phycologist mabe im not sure,  but your doc. will know. thats how you get to him or her, then she will give him a series of tests and talk to him personally and you and mabe even his teacher and together the information to make that diagnosis. good luck. don't put it off. mabe you can call his doctor and ask for the referral. i'm not sure, but he probably wants you and your son in his office tho.