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

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.

Study Overview

• Status: Completed
• Conditions: Stress Disorders, Post-Traumatic; Combat Disorders
• Intervention / Treatment: Behavioral: Exposure therapy; Drug: D-Cycloserine; Other: Placebo pill

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.

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02130
      • VA Boston Health Care system

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: QUADRUPLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: D-Cycloserine; Brief imaginal exposure therapy plus DCS pill	Behavioral: Exposure therapy; A manualized form of treatment that involves vividly visualizing indexed trauma with the guidance of a therapist; Drug: D-Cycloserine; A partial NMDA agonist that has been shown in human trials to facilitate and strengthen extinction with CBT.
Placebo Comparator: Placebo; Brief imaginal exposure therapy plus Placebo pill	Behavioral: Exposure therapy; A manualized form of treatment that involves vividly visualizing indexed trauma with the guidance of a therapist; Other: Placebo pill

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Pre Intervention
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.	Post Intervention
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.	3 month follow-up
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.	6 month follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Pre Intervention
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.	Post intervention
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.	3 month follow-up
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.	6 month follow-up
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.	Pre intervention
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.	Post intervention
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.	3 month follow-up
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.	6 month follow-up

Collaborators and Investigators

• Sponsor: US Department of Veterans Affairs
• Investigators: Principal Investigator: Brett T. Litz, PhD, VA Boston Health Care system

Publications and helpful links

General Publications

• Litz BT, Salters-Pedneault K, Steenkamp MM, Hermos JA, Bryant RA, Otto MW, Hofmann SG. A randomized placebo-controlled trial of D-cycloserine and exposure therapy for posttraumatic stress disorder. J Psychiatr Res. 2012 Sep;46(9):1184-90. doi: 10.1016/j.jpsychires.2012.05.006. Epub 2012 Jun 12.

Study record dates

Study Major Dates

• Study Start: October 1, 2006
• Primary Completion (Actual): September 1, 2011
• Study Completion (Actual): July 1, 2012

Study Registration Dates

• First Submitted: August 31, 2006
• First Submitted That Met QC Criteria: August 31, 2006
• First Posted (Estimate): September 1, 2006

Study Record Updates

• Last Update Posted (Estimate): February 4, 2014
• Last Update Submitted That Met QC Criteria: December 16, 2013
• Last Verified: December 1, 2013

More Information

Terms related to this study

• Keywords: Stress Disorders, Post-Traumatic; Combat Disorders; Cognitive Behavior Therapy; D-Cycloserine; Cognitive enhancers
• Additional Relevant MeSH Terms: Mental Disorders; Pathologic Processes; Trauma and Stressor Related Disorders; Disease; Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic; Combat Disorders; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents; Antimetabolites; Anti-Bacterial Agents; Antitubercular Agents; Antibiotics, Antitubercular; Anti-Infective Agents, Urinary; Renal Agents; Cycloserine
• Other Study ID Numbers: ORD-NIMH-20061