Prevention of Posttraumatic Stress Disorder (PTSD) With Diazepam

Inclusion Criteria: * Outpatients that have experienced an acute event that meets the DSM-IV A.1 PTSD criterion: "the person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others;" * Outpatients that also meet DSM-IV A.2. PTSD criterion: "the person's response involved intense fear, helplessness, or horror;" and * Outpatients that have a heart rate upon ED presentation \>80 BPM * Outpatients that hadn't fallen asleep for a night after traumatic event before ED arrival; Exclusion Criteria: * Physical injury that requires hospitalization, interferes with a patient's ability to cooperate with screening or give informed consent, or otherwise contraindicates participation; * Traumatic event reflecting ongoing victimization (e.g., domestic violence) to which the patient is likely to be re-exposed during the study period; * Head injury with loss of consciousness or amnesia; * Medical condition that contraindicates the administration of diazepam : * hepatic insufficiency, severe * hypersensitivity to diazepam * myasthenia gravis * narrow-angle glaucoma, acute * respiratory insufficiency, severe * sleep apnea syndrome * Current use of medication that may involve potentially dangerous interactions with diazepam, including opioids, barbitals and another benzodiazepines; when used in combination, these drugs have additive CNS and respiratory depressant effects * Women who are currently pregnant or nursing. * Those at immediate risk of harming self or others; those who have a clinically significant medical illness or other significant psychiatric illness; * Overt psychopathology, substance abuse/dependence, intoxication, odor of alcohol, or discernible substance effect;