The character of Dr. Fried is based closely on Greenberg's real doctor Frieda Fromm-Reichmann, and the hospital on Chestnut Lodge in Rockville, Maryland.

While at Chestnut Lodge, Greenberg described a fantasy world called Iria to her doctors, quoting poetry in the Irian language.

[2] However, according to Gerald Schoenewolf, Irian was a conlang invented by Greenberg at an early age to prevent her father from reading her poetry, and had its own writing system resembling Chinese characters.

At that time though, undifferentiated schizophrenia was often a vague diagnosis given to a patient or to medical records department for essentially non-medical reasons, which could have covered any number of mental illnesses from anxiety to depression.

Two psychiatrists who examined the book's description of protagonist Deborah Blau say that she was not schizophrenic, but rather suffered from extreme depression and somatization disorder.