There is a lot of pressure to fit into categories. Most teens don't fit into any one category. While for girls it is more a physical category, for boys it is emotional. Boys are taught to hide their feelings and never admit weakness. Girls at least let it all out, perhaps that is why they attempt more than actually commit.
Boys bottle it up inside until one day they burst.
Instead of looking for answers in the US where teen suicide rates are the highest in the world, let us look at places where they are the lowest. Israel, Mediterranean countries, South American countries. A study done at UC Berkeley linked suicide and depression to weather. Places where it was sunnier, people were happier, period. Europe, Scandinavian countries, and the US are among the highest in suicide ratings.