The paper proves that the heroine of Next to Normal (2010) by Brian Yorkey suffers from hidden psychosis, associated with posttraumatic stress disorder (PTSD) within Cathy Caruth model framework. According to Caruth, the reaction to the crisis is usually delayed, however severe it is in the mind. Its common feature can be seen in flashbacks. This is typical of Diana Goodman, the play's heroine, who is dissociated from reality and who develops hallucination of hearing her dead son's voice every now and then. The trauma of the play's heroine is laid deeply in the unconscious, so her identity appears to be shaken and is on the verge of collapse. She feels guilty to the extent of attempting suicide. As such, the family members – her husband and her daughter- suffer gravely. Though the image is quite gloomy, there is still a glimpse of hope at the end of the play. The paper unfolds the various factors leading to such illness, as well as its stages. It ends with the assertion that Diana's intricate crisis can be reflected in the comorbid features of psychosis and PTSD. It opens possibilities of further research, which is based on interdisciplinary approaches between psychology and literature. It also raises questions regarding the various effects of psychotic disorders on the surrounding society exemplified by care-givers and the whole community surrounding the heroine of the play.