My son was terrorized by his thoughts for a long time before I was able to pick that there was something wrong. He did not verbalize them easily.
One of the early worries, since we are around Christmas, was abouth Santa not being able to land safely on our roof. This was a real, real problem for the little guy.
See, our house has very uneven, multi level roof, and Ghost was calculating that with the speed the reindeers "must be going, to circle the world in two days" (he already knew about the time zones)there was na way they could all safely land on our roof. He was begging husband to build runway extensions in both directions. We were loughing secretely and later became a little unnoyed as he tried to collect wood for runway, but for him it was a huge, huge problem. A psychiatric case for someone who does not know better, right?
Incogneato - he still worries but is not overwhelmed by his worries any more. I think that the toughest time Ghost had at school, when the teachers had no idea why he worries about so many things. I had to explain that this is the problem he is actually having on his burner (the biggest one by far was leukemia), and they were all most likely thinking - what a weird european family. My european mom was however complaining that it was the american culture that was making my son so fragile and vulnerable :-)