 After informed consent is given, fluoxetine 150 subjects or placebo 150 subjects will be administered for 12 weeks in doses from 20 mg daily up to 60 mg daily to active duty soldiers who are already receiving usual psychological care in the Resilience and Restoration Center of the Carl R. Darnall Army Medical Center at Ft. Hood. At the conclusion of this initial phase of the study, all participants will receive fluoxetine in doses up to 80 mg daily for an additional 20 weeks. All participants will be regularly monitored to determine changes in their PTSD symptoms. If a subject does not have at least a 50 improvement after being given 80 mg daily of fluoxetine for 4 weeks, then they will be randomly assigned to also receive either bupropion SR 150 mg daily or buspirone up to 40 mg daily in an attempt to amplify the response to fluoxetine. Statistical analyses will be used to determine which factors provided the greatest influence on the response to these medication trials. 