The most remarkable thing about I Never Promised You a Rose Garden is its fearless portrayal of the mentally ill. Unlike other films dealing with similar subject matter, the characters are not merely caricatures meant to amuse. They are confusing and frightening people, especially for Deborah (Kathleen Quinlan), a young girl with schizophrenia, who is the main focus of the film. Deborah oscillates between the world of the sane and that of the insane; often unable to control her reactions or understand how to word her responses when confronted with something difficult. Her inner world is nearly as frightening as the asylum she inhabits. She creates her own language and race of people who make it their mission to control and manipulate her, constantly accusing her of ‘betraying them’ and warning her that she will be punished if she persists in the betrayal. Her supposed betrayal takes the form of psychotherapy with the kind Dr. Freed (Bibi Anderson).
Deborah longs to experience reality the way others do but is, at the same time, terrified of abandoning her tortuous inner world; she tries to find people who she believes could teach and understand her, the way Dr. Freed does. She meets a patient named Mrs. Coral, who she is told, taught geometry. She soon realises that she will find no one in the asylum, that they are just as trapped and clueless as she is. The hopeless confusion around her forces her to let go of her tormentors and to live in reality. Perhaps the conclusion is too sunny to be realistic but the obstacles on the road make it more acceptable. There is nothing easy about this film, it invokes all the terrors of schizophrenia, never leading the audience to believe in anything but the horror of what Deborah and the people around her experience.