It seems like the good old fashioned christian family bigotry had more to do with it to me. The same shit that almost always tend to leave kids afraid (sometimes rightly so) to tell their parents that they don't believe in their imaginary friends.
Amazing. Whenever somebody commits suicide, it seems the gut instinct is to find somebody to "blame" for causing the family member to do something that seemed impossible. "Surely this boy couldn't be troubled like this, so surely it's Richard Dawkins' fault."
The whole thing is sad. You're right, this boy obviously had nobody to talk to, considering he felt it necessary to hide the copy of the book under his mattress.
And it's also sad that this whole article seems to paint atheism and immorality as the same thing.