Skip to content

A Placebo-Controlled Trial of D-Cycloserine and Exposure Therapy for Combat-PTSD

A Placebo-Controlled Trial of D-Cycloserine and Exposure Therapy for Combat-PTSD

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00371176
Enrollment
26
Registered
2006-09-01
Start date
2006-10-31
Completion date
2012-07-31
Last updated
2014-02-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Combat Disorders, Stress Disorders, Post-Traumatic

Keywords

Cognitive Behavior Therapy, Cognitive enhancers, Combat Disorders, D-Cycloserine, Stress Disorders, Post-Traumatic

Brief summary

The primary aim of this project is to examine whether administration of D-Cycloserine (DCS), a partial N-methyl-D-aspartate (NMDA) receptor agonist that has been shown to facilitate fear extinction, enhances the therapeutic benefit of exposure-based cognitive behavioral therapy (CBT) in OEF/OIF veterans with PTSD.

Detailed description

War-zone-related posttraumatic stress disorder (PTSD) is a major psychiatric disorder that includes specific disabling symptoms and impairments that interfere with a soldier's ability to do his or her job. There is strong evidence for cognitive behavior therapy (CBT) in treating PTSD in civilians, which suggests a prescription for returning veterans, but approximately 40% of patients retain a PTSD diagnosis (e.g., Foa et al., 1999) and drop-out rates are \ 25%. It is imperative to develop novel evidence-based early interventions that are more acceptable to recent veterans and less draining of treatment resources. If CBT can be shortened and its efficacy boosted by cognitive enhancers then it is more likely that soldiers will get the most efficacious treatments for acute stress and PTSD. Our aim is to develop a program that is brief and effective, but will have long-term benefits for veterans by virtue of its greater amenability to self-management and treatment adherence beyond the therapy context. This study is a randomized, controlled, double-blind treatment trial comparing CBT plus DCS to CBT plus placebo. Participants will be 68 OEF/OIF veterans with PTSD randomly assigned to CBT plus DCS or CBT plus placebo. Procedures to screen subjects prior to randomization include a detailed phone screen, administration and collection of questionnaires, a medical assessment, and two baseline structured clinical interviews. Following randomization, both groups will receive the identical 6 session exposure-based CBT protocol. The DCS-augmented group will receive 50 mg of DCS 30 minutes prior to the four CBT sessions involving imaginal exposure, whereas the placebo-augmented group will receive a placebo pill prior to these sessions. Assessment interviews conducted by independent evaluators will occur at pre-treatment, post-treatment, and at 3, and 6-month follow-up. Self-report measures will also be administered at screening, throughout the 6 weeks of treatment, and at 3- and 6- month follow up. Comparison(s): OEF/OIF veterans with PTSD treated with CBT plus DCS, compared to OEF/OIF veterans with PTSD treated with CBT plus placebo.

Interventions

BEHAVIORALExposure therapy

A manualized form of treatment that involves vividly visualizing indexed trauma with the guidance of a therapist

DRUGD-Cycloserine

A partial NMDA agonist that has been shown in human trials to facilitate and strengthen extinction with CBT.

OTHERPlacebo pill

Sponsors

US Department of Veterans Affairs
Lead SponsorFED

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Male or female outpatients 18 years of age or older who served in Operation Iraqi Freedom or Operation Enduring Freedom (OIF/OEF) and who have a primary diagnosis (designated by the patient as the most important source of distress of PTSD. * Willingness and ability to comply with the requirements of the study protocol.

Exclusion criteria

A lifetime history of: * bipolar disorder * schizophrenia * psychosis * delusional disorders or obsessive-compulsive disorder * organic brain syndrome * cognitive dysfunction that could interfere with capacity to engage in therapy * a history of substance or alcohol dependence (other than nicotine) in the last 6 months or otherwise unable to commit to refraining from alcohol use during the acute period of study participation. * Patients with significant suicidal ideation or who have enacted suicidal behaviors within 6 months prior to intake will be excluded from study participation and referred for appropriate services. * Patients must be off concurrent psychotropic medication (e.g., antidepressants, anxiolytics, beta blockers) for at least 2 weeks prior to initiation of randomized treatment. * Serious medical illness or instability for which hospitalization may be likely within the next year. * Patients with a current or past history of seizures * Pregnant women, lactating women, and women of childbearing potential who are not using medically accepted forms of contraception (e.g., intra uterine device, oral contraceptives, barrier devices, condoms and foam, or implanted progesterone rods stabilized for at least 3 months). * Any concurrent psychotherapy initiated within 3 months of baseline, or ongoing psychotherapy of any duration specifically targeting PTSD is excluded. General supportive therapy initiated \> 3 months prior is acceptable. * Patients with seizures or ongoing severe cognitive impairment that compromised mental status. * Patients receiving Isoniazid. * Patients unable to understand study procedures and participate in the informed consent process. * Patients with a history of renal insufficiency (creatinine clearance less than 50 mL/min).

Design outcomes

Primary

MeasureTime frameDescription
Clinician Administered PTSD Scale-IVPre InterventionA 17-item, semi-structured interview of PTSD symptoms. The range of scores is 0-136, with a higher value representing a worse outcome.

Secondary

MeasureTime frameDescription
PTSD ChecklistPre InterventionA 17-item, self-report measure of PTSD symptoms. The range of scores is 17-85, with a higher value representing a worse outcome.
Beck Depression InventoryPre interventionA 21-item, self-report measure of depression symptoms. The range of scores is 0-63, with a higher value representing a worse outcome.

Countries

United States

Participant flow

Recruitment details

The recruitment period was 2007 to 2011. Participants were recruited through VA clinician referrals and public advertising (e.g., flyers and radio ads).

Participants by arm

ArmCount
D-Cycloserine Plus Exposure
Brief imaginal exposure therapy plus DCS pill
13
Placebo Plus Exposure
Brief imaginal exposure therapy plus Placebo pill
13
Total26

Baseline characteristics

CharacteristicPlacebo Plus ExposureD-Cycloserine Plus ExposureTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
0 Participants0 Participants0 Participants
Age, Categorical
Between 18 and 65 years
13 Participants13 Participants26 Participants
Age, Continuous31.62 years
STANDARD_DEVIATION 9.1
32.77 years
STANDARD_DEVIATION 9.85
32.19 years
STANDARD_DEVIATION 9.31
Region of Enrollment
United States
13 participants13 participants26 participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
13 Participants13 Participants26 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
0 / 130 / 13
serious
Total, serious adverse events
0 / 130 / 13

Outcome results

Primary

Clinician Administered PTSD Scale-IV

A 17-item, semi-structured interview of PTSD symptoms. The range of scores is 0-136, with a higher value representing a worse outcome.

Time frame: 6 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureClinician Administered PTSD Scale-IV62.20 units on a scaleStandard Deviation 32.17
Placebo Plus ExposureClinician Administered PTSD Scale-IV55.50 units on a scaleStandard Deviation 27.02
Primary

Clinician Administered PTSD Scale-IV

A 17-item, semi-structured interview of PTSD symptoms. The range of scores is 0-136, with a higher value representing a worse outcome.

Time frame: Pre Intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureClinician Administered PTSD Scale-IV69.85 units on a scaleStandard Deviation 23.24
Placebo Plus ExposureClinician Administered PTSD Scale-IV73.38 units on a scaleStandard Deviation 16.35
Primary

Clinician Administered PTSD Scale-IV

A 17-item, semi-structured interview of PTSD symptoms. The range of scores is 0-136, with a higher value representing a worse outcome.

Time frame: Post Intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureClinician Administered PTSD Scale-IV72.33 units on a scaleStandard Deviation 28.68
Placebo Plus ExposureClinician Administered PTSD Scale-IV53.73 units on a scaleStandard Deviation 26.22
Primary

Clinician Administered PTSD Scale-IV

A 17-item, semi-structured interview of PTSD symptoms. The range of scores is 0-136, with a higher value representing a worse outcome.

Time frame: 3 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureClinician Administered PTSD Scale-IV62.57 units on a scaleStandard Deviation 32.17
Placebo Plus ExposureClinician Administered PTSD Scale-IV58.20 units on a scaleStandard Deviation 26.17
Secondary

Beck Depression Inventory

A 21-item, self-report measure of depression symptoms. The range of scores is 0-63, with a higher value representing a worse outcome.

Time frame: Pre intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureBeck Depression Inventory24.85 units on a scaleStandard Deviation 15.31
Placebo Plus ExposureBeck Depression Inventory21.48 units on a scaleStandard Deviation 9.24
Secondary

Beck Depression Inventory

A 21-item, self-report measure of depression symptoms. The range of scores is 0-63, with a higher value representing a worse outcome.

Time frame: 6 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureBeck Depression Inventory22.25 units on a scaleStandard Deviation 17.73
Placebo Plus ExposureBeck Depression Inventory15.38 units on a scaleStandard Deviation 11.43
Secondary

Beck Depression Inventory

A 21-item, self-report measure of depression symptoms. The range of scores is 0-63, with a higher value representing a worse outcome.

Time frame: Post intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureBeck Depression Inventory28.56 units on a scaleStandard Deviation 16.25
Placebo Plus ExposureBeck Depression Inventory14.18 units on a scaleStandard Deviation 10.81
Secondary

Beck Depression Inventory

A 21-item, self-report measure of depression symptoms. The range of scores is 0-63, with a higher value representing a worse outcome.

Time frame: 3 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposureBeck Depression Inventory24.57 units on a scaleStandard Deviation 14.43
Placebo Plus ExposureBeck Depression Inventory13.90 units on a scaleStandard Deviation 10.59
Secondary

PTSD Checklist

A 17-item, self-report measure of PTSD symptoms. The range of scores is 17-85, with a higher value representing a worse outcome.

Time frame: Pre Intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposurePTSD Checklist37.85 units on a scaleStandard Deviation 8.76
Placebo Plus ExposurePTSD Checklist39.00 units on a scaleStandard Deviation 8.77
Secondary

PTSD Checklist

A 17-item, self-report measure of PTSD symptoms. The range of scores is 17-85, with a higher value representing a worse outcome.

Time frame: 6 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposurePTSD Checklist29.20 units on a scaleStandard Deviation 13.16
Placebo Plus ExposurePTSD Checklist27.25 units on a scaleStandard Deviation 15.83
Secondary

PTSD Checklist

A 17-item, self-report measure of PTSD symptoms. The range of scores is 17-85, with a higher value representing a worse outcome.

Time frame: 3 month follow-up

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposurePTSD Checklist33.29 units on a scaleStandard Deviation 14.68
Placebo Plus ExposurePTSD Checklist26.91 units on a scaleStandard Deviation 16.4
Secondary

PTSD Checklist

A 17-item, self-report measure of PTSD symptoms. The range of scores is 17-85, with a higher value representing a worse outcome.

Time frame: Post intervention

ArmMeasureValue (MEAN)Dispersion
D-Cycloserine Plus ExposurePTSD Checklist34.11 units on a scaleStandard Deviation 21.09
Placebo Plus ExposurePTSD Checklist24.18 units on a scaleStandard Deviation 14.95

Source: ClinicalTrials.gov · Data processed: Mar 26, 2026