Posttraumatic stress disorder (PTSD) is a common and disabling condition. In addition to combat-related PTSD, the disorder occurs in civilians exposed to severe traumatic events, with the community prevalence rate for the combined populations reaching as high as 12%. If left untreated, PTSD may continue for years after the stressor event, resulting in severe functional and emotional impairment and a dramatic reduction in quality of life, with negative economic consequences for both the sufferer and society as a whole. Although PTSD is often overlooked, diagnosis is relatively straightforward once a triggering stressor event and the triad of persistent symptoms-reexperiencing the traumatic event, avoiding stimuli associated with the trauma, and hyperarousal have been identified. However, comorbid conditions of anxiety and depression frequently hamper accurate diagnosis. Treatment for PTSD includes psychotherapy and pharmacotherapy. The latter includes selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and monoamine oxidase inhibitors. Only SSRIs have been proven effective and safe in long-term randomized controlled trials. Current guidelines from the Expert Consensus Panel for PTSD recommend treatment of chronic PTSD for a minimum of 12-24 months.