Anonymous wrote:I think it's a phase that many kids go through. Maybe boys more than girls?
FWIW, my brother was this way from age 12-16. Fully functioning and engaged with the rest of the world, but sullen, angry, antisocial, and withdrawn at home. We'd always been very close, but he was often hard to be around during that period.
Happily, he started coming out of it towards the end of HS and really bloomed in college. No signs of that sullen teenager since then. He's really a joy!
Not the OP, but this is a wonderful story.