As a bilingual (English-English & Canadian-English with a fair amount of knowledge in American-English) I often have to translate family conversations for my trouble & strife (Cockney for wife...). However I've never heard of this particular term. it, being possible from a different region than I. A more common usage would be "going mental". Not common in N.A. granted, but would be easier to understand. You could try reading the book out loud in a thick English accent i do this when I read one of Pour1Malt's posts written in Scots. Then again the family thinks I'm going spare when I'm taking to my computer in a thick Scottish brogue