Effect of D-cycloserine Plus Cognitive Behavioral Therapy on People With Social Phobia

This study has been completed.
Information provided by (Responsible Party):
Stefan G. Hofmann, Boston University
ClinicalTrials.gov Identifier:
First received: August 10, 2007
Last updated: February 4, 2013
Last verified: February 2013

This study will assess the effectiveness of D-cycloserine combined with cognitive-behavior therapy in treating people with social anxiety disorder.

Condition Intervention Phase
Social Anxiety Disorder
Drug: D-cycloserine
Behavioral: Cognitive behavioral therapy (CBT)
Drug: Placebo
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: D-cycloserine Enhancement of Exposure in Social Phobia

Resource links provided by NLM:

Further study details as provided by Boston University:

Primary Outcome Measures:
  • Social Phobic Disorders Severity and Change Form [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]
  • Liebowitz Social Anxiety Scale (LSAS) [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Social Phobia and Anxiety Inventory [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]
  • Quality of Life Enjoyment and Satisfaction Questionnaire [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]
  • Liebowitz Self-Rated Disability Scale [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]
  • Range of Impaired Functioning Tool [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ] [ Designated as safety issue: No ]

Enrollment: 169
Study Start Date: December 2007
Study Completion Date: December 2011
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Participants will receive D-cycloserine augmented cognitive behavioral therapy
Drug: D-cycloserine
50 mg
Other Name: Seromycin
Behavioral: Cognitive behavioral therapy (CBT)
CBT sessions aim to help participants become more comfortable with social situations.
Placebo Comparator: 2
Participants will receive placebo augmented cognitive behavioral therapy
Behavioral: Cognitive behavioral therapy (CBT)
CBT sessions aim to help participants become more comfortable with social situations.
Drug: Placebo
Same dosage as active pill

Detailed Description:

Social anxiety disorder (SAD) is among the most common psychiatric conditions and is associated with significant distress and dysfunction in social situations. Although treatment with cognitive-behavior therapy (CBT) is known to help remedy SAD, many patients do not respond to this treatment and most do not reach full recovery. In CBT, patients undergo repeated and prolonged exposure practices to feared social situations to learn better ways to deal with anxiety in these settings. Exposure therapy is based on animal models of extinction of conditioned fears, and recent animal research has identified some of the core pathways and neurotransmitters involved in fear extinction. D-cycloserine (DCS) is a drug that appears to facilitate learning and the process of extinction of conditioned fear in both animals and humans. This study will assess the effectiveness of DCS combined with CBT in treating people with SAD.

Participants in this double-blind study will be randomly assigned to an active or control group. All participants will attend 18 study visits at the Center for Anxiety and Related Disorders over a 9-month period. There will be 12 CBT sessions of 90 minutes each and 6 assessment visits. The CBT sessions will help participants to become more comfortable with social situations. During 5 of the CBT sessions, participants will receive a pill containing either DCS or sugar (placebo). Assessment visits will include interviews, self-report questionnaires, and laboratory tests. These visits will occur at Weeks 1, 7, and 12 during treatment and at Months 3, 6, and 9 post-treatment.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Meets DSM-IV criteria for generalized social anxiety disorder (GSAD)
  • Total score of greater than or equal to 60 on the LSAS
  • Physical examination, electrocardiogram, and laboratory findings without clinically significant abnormalities

Exclusion Criteria:

  • Lifetime history of bipolar disorder, schizophrenia, psychosis, delusional disorders, or obsessive-compulsive disorder
  • Eating disorder within the 6 months prior to study entry
  • History of organic brain syndrome, mental retardation, or other cognitive dysfunction
  • Substance or alcohol abuse or dependence (other than nicotine) within the 6 months prior to study entry or inability to refrain from alcohol use during the acute period of study participation
  • Post-traumatic stress disorder within 6 months prior to study entry; entry of patients with other mood or anxiety disorders will be permitted if the social anxiety disorder is judged to be the predominant disorder
  • Suicidal thoughts
  • Taking concurrent psychotropic medication (e.g., antidepressants, anxiolytics, beta blockers) within 2 weeks of study entry
  • Significant personality dysfunction
  • Serious medical illness or instability for which hospitalization may be likely within the next year
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00515879

United States, Massachusetts
Boston University
Boston, Massachusetts, United States, 02215
Sponsors and Collaborators
Boston University
Principal Investigator: Stefan G. Hofmann, PhD Boston University
Principal Investigator: Mark H. Pollack, MD Massachusetts General Hospital
Study Director: Jasper A. Smits, PhD Southern Methodist University
  More Information

Responsible Party: Stefan G. Hofmann, Professor, Boston University
ClinicalTrials.gov Identifier: NCT00515879     History of Changes
Other Study ID Numbers: R01 MH078308, R01MH078308, DATR A2-AIR
Study First Received: August 10, 2007
Last Updated: February 4, 2013
Health Authority: United States: Federal Government

Keywords provided by Boston University:
Generalized subtype

Additional relevant MeSH terms:
Anti-Bacterial Agents
Anti-Infective Agents
Anti-Infective Agents, Urinary
Antibiotics, Antitubercular
Antitubercular Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Renal Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on March 30, 2015