Hi there

Well this is really hard to say what is going on not knowing either you or your son.  Some things may be hereditary and some things may be learned from our environment.  There are many things which can cause explosive anger...some children who have ADHD or Oppositional Defiant Disorder may also have issues with anger management.

I just wrote an article you might be interested in reading about how to help children with this sort of anger problem.  Just follow this link.

Whether or not your son has depression...if you have concerns I would start by talking to your son's pediatrician about your worries.  He or she will refer you on to a specialist if they feel it is necessary.

I hope this helps some and thank you for your question.