Thirteen states changed their laws concerning mental health issues after the film's release.
Director Anatole Litvak insisted that the cast and crew spend three months visiting mental institutions and attending psychiatric lectures to prepare themselves for the film. Olivia de Havilland willingly threw herself into the research. She attended patient treatments at the institutions, and observed electric shock therapy and hydrotherapy first-hand. When permitted, she sat in on doctor-patient therapy sessions. She also attended social events for patients at the institutions. After seeing the film, a "Daily Variety" columnist questioned whether any mental institution would really allow violent inmates to dance with each other at a social event. De Havilland personally called the columnist to confirm that she had attended several such dances at institutions.
The character of the gentle psychiatrist was based on the real-life career of Dr. Gerard Chrzanowski, who told his patients to call him simply "Dr. Kik." Dr. Chrzanowski died in November 2000 at age 87.
The New York Film Critics awarded Olivia de Havilland Best Actress for the film. It was the first time since the awards' inception in 1935 that a performer won unanimously. And, as of 2014, the only time.
Mary Jane Ward's book, the basis for this film, was an autobiographical account of the author's experiences in psychiatric hospitals. The book caused considerable controversy upon its publication in 1946, as it was a scathing indictment of the treatment of psychiatric patients, a subject considered taboo in the 1940s. The book was a runaway bestseller.