Dementia is a 1955 American black-and-white experimental horror film produced, written, and directed by John Parker, and starring Adrienne Barrett and Bruno Ve Sota.

It was later acquired by Jack H. Harris, who edited it and incorporated voice over narration by radio personality Ed McMahon (later to be known for co-hosting The Tonight Show with Johnny Carson) before re-releasing it in 1957 under the alternate title Daughter of Horror.

As she runs down an alley, the pimp suddenly grabs her from inside a doorway and drags her into a club; an enthusiastic audience watches a jazz band playing.

[5] Journalist Herman G. Weinberg wrote that the film's lead character suffers from an Electra complex, and is trapped in "a nightmare world in which all good has been routed leaving the girl enveloped in madness, like a protective cocoon.

[8] Parker cast Barrett in the lead role of the Gamin, a young woman wandering through Los Angeles's skid row,[8] in what was initially planned to be a short film.

[9] Parker cast Bruno Ve Sota as the wealthy man the Gamin encounters, and paid him $30 for fifteen hours of shooting.

[10] Though Parker is solely credited as director, writer, and producer, Ve Sota also contributed to the film significantly, serving as a co-writer and co-director.

[4] Dementia was briefly released in 1953[9] before it was banned[11] by the New York State Film Board, who deemed it "inhuman, indecent, and the quintessence of gruesomeness".

[11] As a promotional stunt for the 1955 release, theater employees were required to submit medical examinations of patrons by "heart specialists" to assure that theatergoers would not be frightened to the point of harming their health.

[14] The New York Daily News criticized the film for suffering from a lack of coherence: "The presentation, designed as a shocker, is enough to drive anybody crazy with alternate sessions of tedium and bedlam".

[16] A critic of The New York Times deemed it "A piece of film juvenilia… despite its good intentions… An understanding of Mr. Parker's desire to say something new cannot reconcile one to the lack of poetic sense, analytical skill and cinematic experience exhibited here".

[16] Time Out Film Guide noted: "The movie spends an hour exploring a lonely woman’s sexual paranoia through a torrent of expressionistic distortions which would look avant-garde if the vulgar Freudian ‘message’ weren’t so reminiscent of ’50s B features".

The British Film Institute issued a restored Blu-ray and DVD combination set in October 2020, featuring both the original and re-edited Daughter of Horror versions.

[21] Dementia has also been identified as a feminist film critiquing the violent male-dominated society and subverting the dress code of noir.