well he does fight with depression he's made that public since supernatural first started and it's made him have irrational moments, and random breakdowns even during happy moments. It stemmed from him losing two of his best friends on died the other killed himself. I can relate to that one I went into a spiral like that during high school after my best friend was killed in a hazing gone wrong it can really mess you up. If I remember right, on his way to a comic convention he had a manic breakdown to the point he had to get on a plane to go back to his family quickly.