To compare the short-term and long-term efficacy of two different treatment approaches in widespread use in clinical settings for treating patients with post-traumatic stress disorder (PTSD): fluoxetine (which acts directly on biological systems) vs a psychological treatment, Eye Movement Desensitization and Reprocessing (EMDR). To clarify: 1) the differential treatment effects of these different treatment modalities; 2) whether symptom improvement is accompanied by changes in pathophysiology; and 3) the long-term effectiveness of these treatments.

In recent years a variety of treatment approaches have been shown to be effective in the treatment of PTSD. These include prolonged exposure therapies (PE), stress inoculation training (SIT), EMDR and psychopharmacological treatment with serotonin re-uptake blockers. While PE has been compared with SIT and a study is currently under way comparing cognitive-behavioral treatment with EMDR, no study as yet has compared the relative merits of pharmacotherapy alone vs an exposure treatment. While it is commonly held that, in order to recover, people with PTSD need to "process" their traumatic memories, treatments that do not involve the processing of traumatic memories (such as SIT or pharmacotherapy) may be just as effective. In clinical practice, many patients with PTSD appear to be effectively treated with pharmacological agents alone, without trauma-focused therapy.

Patients are randomly assigned to one of three conditions: 1) a double-blind psychopharmacological treatment (fluoxetine); 2) a manualized treatment which focuses on "processing" traumatic memories (EMDR); or 3) a placebo control group. After 8 weeks of active treatment, subjects are evaluated, cease treatment, and are assessed again after another 8 weeks and at 6 months in order to evaluate the long-term effects. Training raters remain blind to the subjects' treatment condition throughout the study. Treatment outcome is assessed with a multi-modal psychological and biological assessment battery including: 1) standard psychological tests for PTSD (CAPS); 2) neuroendocrine function (cortisol); and 3) psychophysiological response to traumatic scripts (pre-post changes in heart social and occupational functioning). Treatment adherence is monitored throughout the study.