What is the importance of "laudanum" in the book, After Sappho?

Early in the book, laudanum represents the depths of despair and depression that many lesbians face in the 19th and 20th centuries. After her father forces her to marry the man who raped her, Rina Faccio (later known as Sibilla Aleramo) drinks a bottle of laudanum in an attempt to kill herself. The attempted suicide suggests that Sibilla cannot live within a society that suppresses her and forces her to live with a violent and abusive husband. Throughout the novel, the narrator invokes the bottle of laudanum to suggest that various characters feel a sense of hopelessness and anguish.