tent, did he have an incident at school that could have caused him to have major frustrations. My daughter used to do this when people did not believe she was right. She had to be right, she would go to extremes as pulling out the dictionary etc to prove her point. She lost the plot one night because no one agreed with her and she proved through the dictionary she was indeed wrong, that the frustration made her bash her head against her bedroom door - scaring everyone.
I just went in there and took it light heartedly and said to her that she will cause herself a head injury over being wrong in an argument and then she will always be wrong because her brains will be scrambled. Seemed to work.
I try to minimalise and trivialise their BIG PROBLEMS and try to bring in some perspective, as they do not seem to have any a lot of the time.