Carswell's autobiographical debut novel Open the Door! was published in 1922, winning the Melrose Prize and establishing her literary reputation.
In 1922, Catherine Carswell published her first novel, Open the Door!, a semi-autobiographical work tracing the life of a young Scottish woman, Joanna Bannerman, as she seeks emotional and sexual independence against the backdrop of repressive Glaswegian Presbyterian society. The novel had actually been substantially drafted years earlier, with support and encouragement from friends including the novelist Sinclair Lewis.
The book won the Melrose Prize for literature, a significant early recognition that helped establish Carswell's reputation as a serious novelist willing to tackle themes of female sexuality, religious repression, and personal liberation that were considered daring for the period. Its frank treatment of a woman's inner emotional and erotic life marked it as part of the wave of modernist writing challenging Victorian and Edwardian literary reticence.
Open the Door! is now regarded as an important early feminist novel in Scottish literature, notable for its psychological depth and its unflinching portrayal of a woman's struggle against social and familial constraints. The novel's success gave Carswell the confidence and financial footing to pursue further controversial literary work, including her later, more contentious biographical writing.