 Sixty study participants for 30 randomized will be drawn from patients admitted to the Massachusetts General Hospital medicalsurgical inpatient units for a traumatic injury that occurred in the prior 3 weeks. Study participants must meet criteria for the A1, A2 and at least one additional category of Acute Stress Disorder symptoms i.e., B, C and or D criteria, as determined by the Acute Stress Disorder Interview upon initial evaluation, to qualify for randomization in a 12 week, double-blind flexible-dose treatment trial of escitalopram 10-40 mgd versus placebo. 