Origin of the title, according to Roger Corman

I noticed that the trivia section here has some misinformation about the origin of the title. I submitted an update, but figured I'd post it here just in case it isn't accepted.

I just saw Roger Corman interviewed by Ben Mankiewicz on TCM, right before showing Dementia 13.

Roger stated that while the film's title was originally "Dementia", he discovered that there was another film by the same name, so he wanted to alter it. He thought to himself that the number 13 was typically thought of as a scary number, and "Dementia 13" sounded good. He called up Francis Ford Coppola and asked if he could add something to the script about the character having something bad happen to him at the age of 13 that influenced him to be a killer later in life. This would justify the addition of the number. Coppola agreed to do this.