Self-awareness

 

A person's maturity is shown in his self-awareness.  A child looks weak is not only due to his smaller stature, but also his lack of self-awareness.

Your son, due to his condition, is probably at the low end if self-awareness can be measured on a scale, compared to children of the same age.

When something is lacking, the vacuum it left out still needs to be filled.  For a normal child (if such thing exists), that vacuum is filled with nourishment provided by his parents, so that he has a chance to grow physically, emotionally, and developmental-wise.  Hopefully, his self-awareness will expand along the way.

For your son, his receptive mechanism toward those nourishment is selective and restricted; not everything is getting through.  But certain things can latch on easily, like video games.  Over time, his self-awareness will not expand as it should.

Above is a layman's understanding of the problem.

Cannot think of anything that would help other than this:

Ask him to read more (not related to his school work.)  Make sure he has a comfortable chair to sit in with proper lighting in a quiet area.  The first book for him to read is the Bible, children's version.  For a 14-years old, some of the versions can be quite dense but should fit his reading level.  Ask him to tell you what he read, in Genesis, how Adam and Eve become self-aware.

There are also books on saying grace.  Place one next to the dining table.  Have him read a page aloud before each meal.  Learning gratitude is a good thing for a child, he will be happier as a result.