It is based on the non-fiction book Journal d'une schizophrène by Marguerite Sechehaye.

[1][5] It was claimed that the film was also shown to the public during the festival and in Milan before 31 October 1968, however, the Academy of Motion Picture Arts and Sciences ruled that these showings did not constitute a commercial release and ruled the film ineligible as the Italian entry for the Academy Awards.

[5] Shortly after its Venice premiere, Giovanni Grazzini of the Corriere della Sera called Risi's film "perhaps the first Italian film on the merits of psychoanalysis that is able to achieve the double objective of intelligent dissemination and spectacular effectiveness".

[1] The Segnalazioni cinematografiche pointed out Risi's "forceful" style, which, the film's "didactic and scientific intentions" notwithstanding, managed to create an intimate human drama that evokes the viewer's participation.

[1] In his April 1970 article for the New York Times, critic Roger Greenspun titled Diary of a Schizophrenic Girl "a tactfully realized film", pointing out the "clarity of Nelo Risi's images" and "lucidity of Ghislaine D'Orsay's performance" which "excells every other performance I have seen in recent movies".