Hallo.
I had this the movie in HDD, but HDD was failed and I lost all movies.
I search for old black-white movie, I think from east Europe (not sure). It's about boy (about 12-13yo), who is mad, or mentally ill. It's possible, he's only traumatized. I don't know.
In one scene, this boy tries to hang herself on land, and he's rescued at the last moment by his dad or grandpa.
In movie is the scene in which a boy bathes in the shallow river full of stones.
Boy is well-looking, blond and slim and it's one of the best child acting performances I've ever seen.

Great! I found this movie now. But it's no east europe, but France. Poil de Carotte aka The REed Heat.