Effects of Duloxetine on Fear Conditioning in Posttraumatic Stress Disorder (PTSD)

Chronic posttraumatic stress disorder (PTSD) is a debilitating disorder and treatment response to pharmacological interventions has been modest for these patients. Chronic elevated anxiety and associated psychophysiological parameters including increased heart rate and alterations in skin conductance are key symptoms of chronic PTSD. Selective serotonin reuptake inhibitors (SRIs) are considered treatment of first choice for these patients, however a substantial portion of patients treated with SRIs do not respond sufficiently. Therefore, there is a need to establish novel and effective treatment strategies for these patients. Recently, duloxetine has received considerable attention since it was shown in multiple controlled trials to be an effective treatment for people with major depressive disorder (MDD), a condition which is often co-morbid with PTSD. In chronic PTSD, the psychophysiological responses at baseline and in response to treatment with duloxetine have been inadequately studied and may provide novel insight into antidepressant and anxiolytic mechanisms of this compound. Primary Aim 1: Evaluate the anxiolytic and antidepressant effects of duloxetine in patients with chronic PTSD. Secondary Aim 2: Evaluate the effects of duloxetine on fear conditioned psychophysiological responses (including startle eyeblink, skin conductance, and cardiovascular inter-beat interval) at baseline and after 8 weeks of naturalistic treatment in chronic PTSD patients.