PTSD is a trauma-related disorder; symptoms of PTSD include Re-experiencing the trauma (eg, flashbacks, intrusive upsetting thoughts or images) Avoidance (eg, of trauma-related situations, thoughts, and feelings) Negative effects on cognition and mood (eg, persistent distorted blame of self or others, inability to experience positive emotions) Altered arousal and reactivity (eg, sleep difficulties, irritability, concentration problems) For PTSD to be diagnosed, symptoms must last for > 1 month, must not be attributable to the physiologic effects of a substance or a medical disorder, and must significantly impair social and occupational functioning.