A widow deceives her late husband's mother and brothers into thinking he's still alive when she attends the yearly memorial to his drowned sister, hoping to secure his inheritance, but her cunning is no match for the demented, axe-wielding thing roaming the grounds of the family's Irish estate.
You can now watch Dementia 13 online on the following streaming providers in the United States.
| Directing | Francis Ford Coppola | Director |
| Writing | Francis Ford Coppola | Writer |
| Production | Roger Corman | Producer |
| Camera | Charles Hannawalt | Director of Photography |
| Editing | Stuart O'Brien | Editor |
| Editing | Morton Tubor | Editor |
| Production | Marianne Wood | Associate Producer |
| Art | Al Locatelli | Art Direction |
| Directing | Richard F. Dalton | Assistant Director |
| Directing | Jack Hill | Second Unit Director |
| Art | Edward Delaney | Sculptor |
| Editing | Donald Shebib | Assistant Editor |
| Directing | Angela Wadlow | Script Supervisor |
| Sound | Joseph Gross | Sound |
| Sound | Liam Saurin | Sound |
| Art | Eleanor Coppola | Set Supervisor |
| Camera | John Vicario | Camera Operator |
| Art | Paul Julian | Title Designer |
| Crew | Michael Purcell | Other |
| Crew | Patrick Brady | Other |
| Crew | Patrick Doyle | Other |
| Crew | George Brady | Other |
| Camera | Michael Vines | Best Boy Grip |
| Production | Eyemonn Callian | Production Assistant |
| Crew | William Joseph Bryan | Technical Advisor |
| Crew | Jack Hill | Additional Writing |
| Sound | Ronald Stein | Music |
