This thesis compares the depiction of trauma and its psychological effects in two great novels, "The Sun Also Rises" and "The Great Gatsby." The research looks at how the works mirror the period's social and cultural transformations, notably the stigma surrounding mental illness during World War I. The study demonstrates that the characters' PTSD is a driving factor behind their hedonistic lives, rather than a reflection of human fragility. The examination digs further into PTSD symptoms, how they appear in the characters, and how they impact their behavior and relationships. The study analyzes and contrasts the approaches of the two writers, Ernest Hemingway and F. Scott Fitzgerald, to the issue of trauma and PTSD in their works via comprehensive character and theme analysis. The research also looks at how the protagonists in both books cope with their past experiences and how successful these coping techniques are. Finally, the research demonstrates how the characters' PTSD experiences are impacted by their quest for the American Dream and the issue of identity loss. Overall, this thesis sheds light on the complex nature of human psychology as well as the difficulties of readjusting to life after trauma and war.