I have a 12 yr old son, and this year he seems especially not interested in his schoolwork. i have to be "on him" all the time, and when he does his work, he's a straight A student, what bothers me about my son is his attitude, he just doesnt seem to care. he shrugs his shoulders alot. like your son, he s a good kid, a great brother, so its not like hes acting out at home, kwim? i have found out though, that his lack of interest and poor motivation is because the schoolwork is so boring, so easy for him, as his label is "gifted". he also says "mom, its not like i cant do it, but, why should i? i already know how, and its not like the teacher gives a care".
i have spoken to his teachers, and they have changed how they teach him, and changed the assignments they have given him. he is now excited anout a science project that includes tracking mice, and how they grow etc. He hates spanish, and can not only speak it fluently, but also speaks germn fluently as well, so instead of failing him, they moved him to french class, and he is much happier.
maybe your friend can see what the teachers can do to inspire him and motivate him....and when this boy is motivated and excited about learning, the grades and completed homework assignments "will come".