My younger brother is a student of engineering and is away from home. Earlier he was feeling very home sick but slowly and gradually he has started developing no feelings for anybody. Not for parents, friends, close relatives. He complains about having no reason to laugh or to cry. We consulted doctors and they said he is into depression. But i am not able to understand what kind of depression is it? As he knows and is able to understand everything. He is not able to concentrate and says that if somebody tells him to jump he will jump without thinking. Moreover he says that he hasno fear about anything in his mind which he was having earlier. Please suggest something.