Star Joan Crawford reportedly said, "I will not go on with this picture unless the Epstein Boys rewrite my part." Twin brothers Julius J. Epstein and Julius J. Epstein were then on suspension from the studio. In order to get them to accede to Crawford's demands, executive producer Jack L. Warner had to take them off suspension and give them back pay for their uncredited rewrite Crawford wanted.
Joan Crawford and director Curtis Bernhardt spent time in real psychiatric wards in Santa Monica, Santa Barbara, and Pasadena, observing mental patients as research for the film and going over the script with doctors for the sake of authenticity. On one of those visits, Crawford and Bernhardt witnessed, without asking permission, a woman undergoing electroconvulsive therapy. Warner Bros. was later forced to pay substantial damages to the woman, who claimed their presence was an invasion of privacy. She also claimed that Crawford based the role on her.
Silvia Richards wrote the first draft of the screenplay for the film. However, in order to try and repeat the success of El suplicio de una madre (1945), producer Jerry Wald hired Ranald MacDougall to do a complete rewrite.
The second film with this title Joan Crawford appeared in. The first was the 1931 film Amor en venta (1931), co-starring a young Clark Gable. This makes Crawford the only star to appear in two completely different films with identical titles.
Joan Crawford spent six weeks in hospitals watching schizophrenics, seeing how sodium pentothal and sodium Amytal restores them to memory for a few brief moments--six weeks at L.A. General Hospital, and many sanatoriums.