In his book Godfather: The Intimate Francis Ford Coppola, Gene D. Phillips quotes Roger Corman on the set-up for shooting another feature on the British Isles following The Young Racers (1963): Corman had outfitted a Volkswagen minibus with filming equipment; "We had the minibus with the cameras, lights, and dollies... What we didn't have was a work permit. The most logical place to shoot the film was Dublin, because we could just ferry the minibus over from Liverpool. Ireland was much looser with labor permits."

Several of Coppola's friends and fellow UCLA film students came to Ireland for the Dementia 13 shoot. One was John Vicario, the camera operator. Vicario brought his girlfriend, Eleanor Neil, who had studied at the UCLA Art Department; she was put to work on the film as a set decorator. During the shoot Neil's romance with Vicario cooled and she began dating Coppola. The two were married in Las Vegas on February 2, 1963. Eleanor later shot the footage that made up the behind-the-scenes documentary Hearts of Darkness: A Filmmaker's Apocalypse (1991).

In addition to having Jack Hill add more scenes to Dementia 13 in post-production, producer Roger Corman also shot a 5-minute gimmick prologue. An actor posing as a psychiatrist gave the audience a "D-13 Test" before the film, asking such questions as "Are you afraid of death by drowning?" and "Have you ever attempted suicide?" This promotional gimmick was only seen in the original theatrical showings of the film.

Dementia 13 actress Mary Mitchel told interviewer Tom Weaver (in Earth vs. the Sci-Fi Filmmakers: Twenty Interviews by Tom Weaver) "I could tell when I read the script that it was going to be a good horror film. I still think that. It just had more going for it. And I remember when I was doing it, I was happy to be there, and thought it would be good. Again, I didn't think it'd be a great film – we didn't have a lot of money. But I think that Francis was able to give it some production value."

Dementia 13 co-star Mary Mitchel on producer Roger Corman and the kinds of breaks he gave to aspiring filmmakers like Francis Coppola: "At the time, the studios had no interest at all in young filmmakers. Nobody came out of the universities, nobody was considered to be knowledgeable or be of any value at all. In fact, [young filmmakers] were totally barred from any kind of jobs whatsoever, couldn't get near a studio or a set. There was no mentoring... 'cause there was nothing in it for the old guard. There was only one person who offered young actors and filmmakers an opportunity, and that was Roger Corman. His was the only company where you could get a foothold."

Compiled by John M. Miller

SOURCES:
Francis Ford Coppola: Interviews, Edited by Gene D. Phillips and Rodney Hill. 2004, University Press of Mississippi.
Roger Corman: Blood-Sucking Vampires, Flesh-Eating Cockroaches, and Driller Killers by Beverly Gray. 2004, Thunder's Mouth Press.
Godfather: The Intimate Francis Ford Coppola, Gene D. Phillips. 2004, The University Press of Kentucky.
Earth vs. the Sci-Fi Filmmakers: Twenty Interviews by Tom Weaver. 2005, McFarland.