Prevalence Of Posttraumatic Stress Disorder Symptoms In Firefighters . Posttraumatic stress disorder (PTSD) is serious mental illness characterized by symptoms of avoidance and nervous system arousal after experiencing or witnessing a traumatic event. Symptoms of posttraumatic stress disorder (PTSD) have been extensively studied in victim populations (e.g., survivors of sexual assault), but not nearly as thoroughly in the responders who come to the aid of those victims, particularly firefighters. First Responder PTSD and Suicides, and the Silence That ... (Stephen Rodriguez) Posttraumatic stress disorder (PTSD) is serious mental illness characterized by symptoms of avoidance and nervous system arousal after experiencing or witnessing a traumatic event. To manage posttraumatic stress symptoms in early and mid-life, individuals may engage in avoidance-based coping strategies (such as drinking alcohol or over-committing oneself to work) that are less available or