...his attention is lost most of the time. I ask him to do something , he may come 15 minutes later to ak me what it was that I have asked him to do !
...he stilllacks basic social skills.
My son is...lost soemwehre else. He knows Math and physics, but needs to learn to say "Hello" and "How are you" . He is good and kind, but generally childish in his behaviour.
This sounds very much like the way I was at 14, as well as most of my friends. Signs of being violent, or signs of drug or alcohol use should be the big red flags. By all means consult a doctor if you think it's proper, but weigh any suggestions to medicate him most carefully.