Use of an Antibiotic as an Enhancer for the Treatment of Social Phobia

Phase 2

Completed

Conditions: Social Phobia
Anxiety
Phobic Disorders

Interventions: Drug: Placebo
Drug: D-Cycloserine

Registration Number: NCT00128401

Lead Sponsor: National Institute of Mental Health (NIMH)

Brief Summary: This study examines whether an antibiotic, d-cycloserine (DCS), boosts the effectiveness of cognitive behavior therapy (CBT) for social anxiety. CBT has been shown to be effective for the treatment of social anxiety in children and adults, but even after treatment, approximately 40% may remain diagnosable. The antibiotic DCS has been shown to enhance the type of learning that is promoted by exposure therapy, a main component of CBT. This study will test whether DCS can improve the effectiveness of CBT for social anxiety.

All participants will receive 12 weekly CBT sessions. In addition to receiving the CBT, participants will be randomly assigned (similar to a coin toss) to receive either DCS or a placebo (sugar pill). The pill will be taken 1-2 hours prior to each of the 12 CBT sessions. The pill is taken only on the 12 therapy days.

Prior to receiving treatment, participants will be asked to:

* participate in interviews to assess diagnosis and how they are doing including mood, degree of nervousness and behavior

* have a physical examination, a urine test, and an electrocardiogram (EKG)

* undergo tests involving problem-solving and memory

* prepare and present a speech to a "virtual audience" using virtual reality goggles

* undergo functional magnetic resonance imaging (fMRI) while performing tasks that involve looking at pictures, remembering things, testing reaction times, and making simple choices

Those who have not improved by the end of the study will be offered standard antianxiety medication treatment for 1 to 3 months. If a participant does not wish to take medication, study clinicians will help him/her locate psychological care in the community. Participants will be asked to complete a follow-up assessment 3 months after their last CBT session.

Detailed Description: Social phobia afflicts between 3%-15% of the US population. As such, it is a particularly common debilitating psychiatric disorder. Like many anxiety disorders, social phobia typically arises during adolescence. Treatment has consisted of medication or cognitive behavioral therapy (CBT). Selective Serotonin Reuptake Inhibitors (SSRIs) represent the first-line pharmacological treatment both in adults as well as adolescents (APA Treatment Guidelines 2004). Similarly, CBT significantly improves outcome in both age groups. This treatment consists of psychoeducation, exposure therapy, and cognitive restructuring. While both treatments produce clinically meaningful benefits, most patients exhibiting positive responses to these treatments continue to exhibit marked residual symptoms, if not full-blown anxiety disorders. Thus, there is great need for treatment advances.

Intense fear of social scrutiny represents a core component of social phobia, and extinction of this fear represents the goal of exposure therapy during CBT (Cohn and Hope). Finding treatments that facilitate extinction is of paramount importance. In animals, extinction involves an active learning process that is blocked by glutamatergic NMDA antagonists and facilitated by NMDA agonists. Specifically, administration of D-cycloserine (DCS), a partial agonist at the glycine modulatory site on the NMDA receptor, produces a dose-dependent facilitation of extinction in the rat. As such, DCS might facilitate extinction during exposure-based CBT. Indeed, Ressler (Ressler et al 2004) recently reported preliminary data from a clinical trial supporting this hypothesis.

We will examine the degree to which DCS treatment can augment the clinical response in social phobia to CBT-exposure-based therapy. Specifically, we will study two groups of individuals with social phobia, both of whom will receive CBT. One group will receive placebo; a second group will receive 50 mg of D-cycloserine 1-2 hours before each exposure therapy session. We hypothesize that compared to placebo, DCS will produce greater reductions in social anxiety symptoms following CBT treatment. Finally, given that chronic social anxiety disorder virtually always begins during childhood, it is particularly vital to develop early interventions for the disorder. Accordingly, our trial will examine both adolescents and adults with the disorder.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 48

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Another group was given the placebo and tested for effectiveness of cognitive behavior therapy (CBT) for social anxiety.
D-Cycloserine	D-Cycloserine	An antibiotic, d-cycloserine (DCS) was given to one group and the group is evaluated to see if the drug boosts the effectiveness of cognitive behavior therapy (CBT) for social anxiety.

Primary Outcome Measures

Name	Time	Method
Clinical Global Improvement (CGI-S) Scale	12 weeks post baseline	Symptom severity and improvement was assessed using the Clinical Global Impressions scale (CGI). It is a 2-item clinician-administered instrument that measures the patients' illness severity and global improvement. The minimum value for the CGI is 1=Normal, not at all ill and the maximum value is 7=Among the most extremely ill patients.

Secondary Outcome Measures

Name	Time	Method
Liebowitz Social Anxiety Scale (LSAS)	12 weeks post baseline	Social anxiety symptoms were assessed using the Liebowitz Social Anxiety Scale (LSAS). It is a 24-item self-report instrument that measures overall social anxiety fear and avoidance symptoms. This is the baseline assessment. The 24 items are each rated twice, from a "0" to "3" scale, with "0" indicated no level of symptom and "3" indicating a high level of the system. One rating is for anxiety, and the other is for avoidance. Thus, the lowest possible score is 0, and the highest possible score is 144. The total score represents the simple sum of all 48 ratings.