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

This study has been completed.
National Institute of Mental Health (NIMH)
Information provided by (Responsible Party):
Stefan G. Hofmann, Boston University Identifier:
First received: August 10, 2007
Last updated: July 20, 2015
Last verified: July 2015
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
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, 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 (immediately after treatment) ]
    Social Phobic Disorders Severity and Change Form (SPD-SC Form; Liebowitz et al., 1992) is an expansion and adaptation of the Clinical Global Impression Scale (CGI) by Guy (1976) to SAD. Similar to the original CGI scale, the SPD-SC Form is rated by an independent evaluator on a 7-point scale to indicate severity (1=normal/not ill; 2 = minimally ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most severely ill) and improvement (1=very much improved; 2=much improved; . 3=minimally improved' 4 = no change; 5=nimimal deterioration; 6=severe deterioration; 7=very severe deterioration). The primary outcome measure is units of a scale ranging from 1 (very much improved) to 7 (very severe deterioration).

  • Liebowitz Social Anxiety Scale (LSAS) [ Time Frame: Measured at Months 3 ]
    The Liebowitz Social Anxiety Scale (LSAS; Liebowitz, 1987) is a 24-item scale that provides separate scores for fear and avoidance in social and performance situations; it is widely used in treatment studies of SAD. Total scores range from 0 (no anxiety) to 144 (maximum).

Secondary Outcome Measures:
  • Social Phobia and Anxiety Inventory [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ]
  • Quality of Life Enjoyment and Satisfaction Questionnaire [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ]
  • Liebowitz Self-Rated Disability Scale [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ]
  • Range of Impaired Functioning Tool [ Time Frame: Measured at Months 3, 6, and 9 post-treatment ]

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: CBT plus d-cycloserine
Participants will receive cognitive behavioral therapy plus D-cycloserine
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: CBT plus placebo
Participants will receive cognitive behavioral therapy plus pill placebo
Behavioral: Cognitive behavioral therapy (CBT)
CBT sessions aim to help participants become more comfortable with social situations.
Drug: Placebo
Same dosage as active pill
Other Name: Sugar 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   (Adult, Senior)
Sexes Eligible for Study:   All
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 identifier: NCT00515879

United States, Massachusetts
Boston University
Boston, Massachusetts, United States, 02215
Sponsors and Collaborators
Boston University
National Institute of Mental Health (NIMH)
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

Additional Information:
Responsible Party: Stefan G. Hofmann, Professor, Boston University Identifier: NCT00515879     History of Changes
Other Study ID Numbers: R01MH078308 ( US NIH Grant/Contract Award Number )
R01MH075889 ( US NIH Grant/Contract Award Number )
Study First Received: August 10, 2007
Results First Received: August 2, 2013
Last Updated: July 20, 2015

Keywords provided by Boston University:
Generalized subtype

Additional relevant MeSH terms:
Anxiety Disorders
Phobic Disorders
Mental Disorders
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Molecular Mechanisms of Pharmacological Action processed this record on May 23, 2017