My son started a new secondary school in September and all went really well. He made loads of friends, got stuck in to work and really appeared to be happy. At the start of the second term these friendships kind of unravelled - he's still doing well but overall seems less happy and more emotional and on a short fuse. I've heard of second-term blues at Uni - but wonder if any other parents are noticing it with their Year 7 kids this second term?
I am think you may be right. DS's friendships from the first term have become looser. He told us that as he learns more about his new friends he isn't so keen and he has drifted away from the pack. Also school life has become more humdrum and the novelty has worn off, he has got into a bit of a stew about his work because he has to be on top of it all the time and is more moody and stroppy at home, although I do think puberty is on it's way as well!
This happened with DS1, though the boys he had problems with had been friends since primary school. I think there was a lot of bravado amongst some of the boys in Year 7. They started feeling they had to act cool and 'ard now they were in Secondary School. It wore off though and he's still friends with them now.
DS2 didn't have his Primary school friends with him and it did take him a while to find friends he could relate too. He's quite quiet. He got there eventually though.
Another issue is that I think the schools stop making allowances in term two and things feel more serious. I know that in Term 1, DS2 said he preferred Secondary School to Primary but then said in Term 2 that definitely wasn't the case anymore.
They're now in years 8 and 11, and pretty much take it all in their stride though DS2 still gets upset about one very "shouty" teacher.
Another thought. It might be worth chatting to him at a quiet time during half term and find out if there is anything specific bothering him. I find my boys more open about that kind of things when we're maybe cuddled up together having watched a film on a weekend or holiday, than during the whirlwind of pre-school and post-school activity.