Inclusion Criteria:

• 1. Age ≥ 18 years
• 2. Weight: 99 lb - 242 lbs
• 3. Experienced a traumatic event less than 6 hours ago

Inclusion Criteria:

• ED staff note marked anxiety emotional distress and or dissociation in relation to index trauma as assessed by meeting a minimum of 2 out of 4 of the peritraumatic characteristics that have been associated with the development of PTSD below:
• 1. Anxiety Visual Analog Scale minimum score of 4 on a scale of 0 to 10
• 2. Peritraumatic dissociation (PDEQ) with a cut-point of 15 (lowest possible score is 10)
• 3. Peritraumatic distress (Peritraumatic Distress Inventory) (PDI) with a cut-point of 15 (lowest possible score is 0)
• 4. Heart rate at 80 bpm or more

Exclusion Criteria:

• 1. Severe physical injury as assessed with the Abbreviated Injury Scale (AIS \> 2); Examples include severe burn injury, life-threatening medical or surgical condition, condition requiring surgical intervention under general anesthesia, as indicated by clinical judgment.
• 2. Inability to provide informed consent or cooperate with the screening or collection of initial measures.
• 3. Intoxication to a degree that would interfere with the ability to provide informed consent or high level or intoxication reported at the time of trauma.
• 4. Moderate to severe head injury associated with current trauma exposure as defined by a loss of consciousness \>30 minutes following injury.
• 5. Medical conditions e.g., Cushing's syndrome, current acute infectious or viral disease, tuberculosis, unstable diabetes or hypertension, myasthenia gravis, heart failure.
• 6. Currently taking oral steroids
• 7. Use of benzodiazepine within 24 hours of trauma exposure will not be eligible to participate in the study
• 8. Individuals prescribed a narcotic medication to alleviate acute pain in the ED will not be eligible to participate in the treatment study.
• 9. Weight below 45kg or above 110 kg (99 lbs - 242 lbs)
• 10. Pregnancy (a urine pregnancy test will be performed in the ED)
• 11. Individuals experiencing on-going trauma (i.e., domestic violence).
• 12. Reported diagnoses of schizophrenia, bipolar I disorder, or other psychotic illness.
• 13. Current or past history of dementia, amnesia or other cognitive disorder predating trauma exposure
• 14. Residence outside local area, which would hinder attendance at follow up visits due to long travel time.