Inclusion Criteria:

• Male or Female
• Between 18 and 65 years old
• Have experienced one or more traumatic events within the last year €Examples for traumatic events include physical or sexual assault, combat, natural disasters, witnessing death or injury of another person, bereavement €Currently experiencing severe symptoms of anxiety including flashbacks and intrusive memories of the traumatic event. €Not currently pregnant or intending to become pregnant. If sexually active, participants must be using an approved form of birth control
• Medically healthy
• Not currently taking psychiatric medications

Exclusion Criteria:

• > Lifetime or current diagnosis of schizophrenia or other psychotic disorder, bipolar disorder, or current Axis I disorder (except for major depression secondary to the PTSD)
• Current evidence or history of significant unstable medical illness or organic brain impairment, including stroke, CNS tumor, demyelinating disease, cardiac, pulmonary, gastrointestinal, or renal or hepatic impairment.
• Patient who in the investigator¹s judgment pose a current suicidal or homicidal risk
• DSM-IV substance abuse or dependence within the past 90 days
• Patient has been taking psychotropic medication in the last 2 weeks (5 weeks for fluoxetine) prior to screening. Psychotropic medications in the last 2 weeks prior to screening, fluoxetine in last 5 weeks.
• Treatment with any other concomitant medication with primarily CNS activity
• Treatment with any medication that the PI considers not acceptable for this study.
• Patient regularly, or on average, drinks more than a) 28 units of alcohol per week for male patients, or b) 21 units of alcohol per week for female patients (1 unit = 1/2 pint of beer, or 1 glass of wine, or 1 measure of spirit)
• Pregnancy or lactation*
• Patient is currently receiving evidenced-based structured psychotherapy (e.g., cognitive-behavioral therapy, exposure therapy).