Trial is no longer enrolling due to priority of other non-pharmacologic PTSD trials.

This study proposes to evaluate the effects of D-cycloserine (DCS) combined with cognitive-behavioral treatment with exposure therapy in a sample of patients who developed posttraumatic stress disorder (PTSD) as a consequence of various traumas (e.g., motor vehicle and accidents, burns and other injuries, combat, World Trade Center attack, etc.). In addition, this study hopes to determine whether a common human genetic single nucleotide polymorphism (SNP) in a growth factor, brain derived neurotrophic factor, BDNF SNP (Val66Met), predicts treatment response to PTSD.

Patients living in areas that are not geographically proximal to the Weill-Cornell Medical Center New York City campus will receive cognitive behavioral therapy using telemedicine (videoconferencing technology).

Overall, this study aims 1) to determine if subjects administered DCS show a significantly larger decrease in symptoms of PTSD as compared to those administered a placebo, 2) to determine if subjects administered DCS show a decrease in PTSD symptomatology significantly earlier (as measured by weeks) than those administered a placebo, 3) to determine if differences in symptomatology are evident at a 6-month follow-up and indicate long-term differences between groups, 4) to determine if the BDNF SNP predicts treatment response, 5)to determine if it is feasible and acceptable to provide imaginal exposure (IE) therapy for PTSD using videoconferencing technology.

Following an initial assessment evaluating eligibility for the study, eligible participants will be randomly assigned to one of two treatment groups: imaginal exposure (IE) plus DCS (100mg) or IE plus placebo (sugar pill). DCS is a broad spectrum antibiotic that has recently been implicated as a cognitive enhancer and may enhance the treatment that occurs. The participant, assessor and treating clinicians will be blinded to which pill the participant is receiving. The dose of medication will need to be taken only on the days of therapy sessions during which the exposure occurs (approximately 9 times). Both groups will be treated with a standardized cognitive-behavioral exposure therapy protocol utilizing gold-standard treatment, consisting of 12-14 weekly individual (one-on-one) sessions with a highly qualified clinical psychologist. Treatment interventions include imaginal exposure, graduated in vivo exposure, psycho-education, relaxation training, behavioral activation, and cognitive restructuring. Assessments will occur prior to treatment, following sessions 3, 6 and 10, following completion of treatment, and 6 months after the conclusion of treatment. In addition, all participants will be genotyped once for the BDNF SNP (Val66Met) using a non-invasive saliva sample.

Inclusion Criteria:

1. English-speaking adults
2. Age 18-70
3. Survivor of a variety of traumas (e.g., motor vehicle and accidents, burns and others injuries, combat, World Trade Center attack, etc.)
4. Diagnosed with PTSD
5. In good health. For persons with chronic injuries/conditions related to their accidents, "good health" is defined as the injury being in a state of stabilization and able to attend weekly outpatient sessions.

Exclusion Criteria:

1. Current organic mental disorder
2. Schizophrenia or symptoms of psychosis/delusions
3. Bipolar disorder
4. Current substance abuse or dependence
5. Active suicidal/homicidal ideation, intent, or plan
6. Use of pacemaker
7. Significant health impairment, including renal disease
8. Taking oral anticoagulant medication, ethionamide (Trecator-SC), isoniazid (INH), or anti-depressant medication
9. Hypersensitivity to cycloserine
10. History of seizures
11. Pregnant or currently trying to conceive, or breastfeeding

14 weeks