"As these are private texts there was a lot ... in context," he said.
"It's important to know none of that was ever intended to be real and the language used which ... yes, I am ashamed (of) has to be spread on the world like peanut butter.
"For example, the text that is about burning Ms Heard is directly from Monty Python and the sketch about burning witches and then drowning the witches.
"This is a film we'd all watch when we were 10 - it's just irreverent and abstract humour."
Mr Depp added that the relationship between Mr Bettany and Ms Heard was "abominable" as she viewed him as a "threat".
He said: "Ms Heard despised Mr Bettany mainly because we had become such close friends and for her he was a threat and would take me away from her."