• PTSD symptoms [ Time Frame: Measured at Months 3, 6, 12, and 24 post-treatment ] [ Designated as safety issue: No ]
  
• Depression symptoms [ Time Frame: Measured at Months 3, 6, 12, and 24 post-treatment ] [ Designated as safety issue: No ]
  
• Anxiety symptoms [ Time Frame: Measured at Months 3, 6, 12, and 24 post-treatment ] [ Designated as safety issue: No ]
  

• Quality of life functioning [ Time Frame: Measured at Months 3, 6, 12, and 24 post-treatment ] [ Designated as safety issue: No ]
  

Exposure to traumatic events, such as automobile accidents and assault, can cause individuals to develop persistent psychological difficulties such as post-traumatic stress disorder (PTSD). PTSD is an anxiety disorder characterized by avoidance, hyperarousal symptoms, and mental re-experiencing of the traumatic event. PTSD is a serious condition that may cause social and psychological impairment; therefore, safe and effective treatments are needed. Both CBT and antidepressant therapy have been shown to effectively treat PTSD symptoms; however, comparisons of the treatments are limited. This study will compare the short- and long-term effectiveness of CBT and the antidepressant sertraline.

Participants will either be randomly assigned to CBT or sertraline, or they will be able to choose one of the two treatments, which will be given for 10 weeks, followed by 24 months of follow-up assessments. Participants in the CBT group will have 10 weekly sessions of therapy. During the therapy sessions, participants will be encouraged to confront their general fears and the memory of their trauma through repeated storytelling. Participants will also be encouraged to practice the techniques learned in therapy in everyday life. Participants in the antidepressant group will take sertraline daily for 10 weeks. These participants will be seen weekly by a psychiatrist who will offer general encouragement and support, monitor response to medication, and record any side effects participants may be experiencing. The medication may be adjusted according to a dosing schedule and based on the study doctor's judgment. At the end of 10 weeks, participants in the antidepressant group will have the choice of either tapering the medication gradually to minimize the chance of withdrawal symptoms or staying on the medication for up to 24 months. Participants who do not respond to their assigned or chosen treatment will be offered the other treatment for 10 weeks. Self-report scales and questionnaires will be used to assess participants' PTSD symptoms, depression, anxiety, and social functioning. These assessments will occur at 3, 6, 12, and 24 months after the study treatment period.

Study hypothesis: Both sertraline and cognitive behavior therapy (CBT), or prolonged exposure, will reduce symptoms of PTSD.

Inclusion Criteria:

• DSM-IV diagnosis of PTSD
• Experienced traumatic event at least 12 weeks prior to study entry
• Willingness to discontinue current CBT or antidepressant treatment

Exclusion Criteria:

• Current diagnosis of schizophrenia or delusional disorder
• Medically unstable bipolar disorder, depression with psychotic features, or depression requiring psychiatric treatment
• Current diagnosis of alcohol or substance dependence within 3 months prior to study entry
• Ongoing intimate relationship with the perpetrator of the traumatic event
• History of nonresponse to either CBT or sertraline
• Medical contraindication for sertraline