• Clinician Administered PTSD Scale Pre-and Post-tx;3,6,12 month FU
• psychophysiological measures Pre-and Post-tx;3,6,12 month FU
• PTSD Symptom Scale Self-Report Pre-and Post-tx;3,6,12 month FU
• Cognitive Global Impressions each session; post-tx, 3,6,12 month FU
• Quality of Life Inventory Pre-and Post-tx;3,6,12 month FU
• State-Trait Anxiety Inventory Pre-and Post-tx;3,6,12 month FU
• Beck Depression Inventory Pre-and Post-tx;3,6,12 month FU

• Psychophysiological measures [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6, and 12 follow-ups ] [ Designated as safety issue: No ]
• PTSD Symptom Scale Self-Report [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6 and 12 follow-ups ] [ Designated as safety issue: No ]
• Clinical Global Impressions Scale [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6, and 12 follow-ups ] [ Designated as safety issue: No ]
• Quality of Life Inventory [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6, and 12 follow-ups ] [ Designated as safety issue: No ]
• State-Trait Anxiety Inventory [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6, and 12 follow-ups ] [ Designated as safety issue: No ]
• Beck Depression Inventory [ Time Frame: Measured at pre- and post-treatment and at Months 3, 6, and 12 follow-ups ] [ Designated as safety issue: Yes ]

This study will determine whether a combination of virtual reality exposure therapy and D-cycloserine will reduce post-traumatic stress disorder symptoms in Iraq war veterans.

Post-traumatic stress disorder (PTSD) is a type of anxiety disorder affecting people who have witnessed or experienced a traumatic event. Veterans of war are at an increased risk for developing PTSD because of their experiences with war and combat. Symptoms of PTSD often include flashbacks or nightmares, depression, anxiety or uneasiness, and feeling emotionally numb or distant toward others. Fortunately, PTSD can be treated, usually with some combination of anti-depressants, anti-anxiety medication, and therapy. Virtual reality exposure (VRE) therapy is a new type of treatment that helps people to overcome anxiety about trauma by facing situations with the use of virtual reality. D-cycloserine is a medication that has been found to enhance the effects of psychotherapy in recent studies. This study will determine the effectiveness of VRE therapy plus D-cycloserine at reducing PTSD symptoms in Iraq war veterans.

During this study, all participants will undergo one educational session and five VRE sessions. The first session will involve gathering information, learning common reactions to trauma, and participating in a breathing relaxation approach. The following five sessions will involve reviewing memories of Iraq and watching virtual Iraq sequences. Each participant will wear a head-mounted display during which they will view scenario settings such as cities, humvee convoys, and scenes related to combat. Participants will be randomly assigned to receive D-cycloserine, alprazolam (anti-anxiety drug), or placebo one half-hour before each VRE session.

Prior to the first treatment session, participants will undergo a startle reaction procedure. This will entail hearing sudden tones that last a fraction of a second, and viewing virtual reality scenes. Three small electrodes, attached to each participant's face, will measure the number of eye blinks during the procedure. At several times throughout the study, heart rate and skin conductance will also be measured with electrodes. Collection of saliva samples and measurement of blood pressure will also occur several times during this study. Before, during, and immediately after treatment, participants will complete questionnaires. Participants will be contacted 3, 6, and 12 months after treatment to assess symptoms and to schedule a time for an interview, additional questionnaires, and the virtual reality-based assessment.

• Drug: D-Cycloserine
• Drug: Alprazolam
• Behavioral: Virtual Reality Exposure Therapy
• Drug: Placebo

• Experimental: Participants will receive VRE therapy and D-cycloserine
• Active Comparator: Participants will receive VRE therapy and alprazolam
• Placebo Comparator: Participants will receive VRE therapy and placebo

Inclusion Criteria:

• Meets DSM-IV criteria for PTSD due to Iraq military trauma
• Speaks English
• Healthy overall

Exclusion Criteria:

• History of mania, schizophrenia, or other psychoses
• Suicidal
• Current alcohol or drug dependence
• Medication free within 2 weeks of study entry for any medication that has been taken less than daily for the past month and medicine free within 4 weeks of study entry for any anxiolytic medication that has been taken daily for the last month or more
• Pregnant
• Special medical conditions, such as kidney insufficiency, chronic diseases, or history of significant head injury
• Stabilized on potentially data obscuring medication such as glucocorticoids