Exposure, D-cycloserine Enhancement, and Functional Magnetic Resonance Imaging (fMRI) in Snake Phobics

Not Applicable

Completed

• Conditions: Specific Phobia
• Interventions: Drug: D-cycloserine; Behavioral: Exposure therapy; Drug: Placebo

• Registration Number: NCT01450306
• Lead Sponsor: Hartford Hospital

Brief Summary

The aim of the present study is to determine whether people receiving d-cycloserine and exposure therapy show different brain reactions to symptom provocation compared to people receiving placebo and exposure therapy.

Detailed Description

D-cycloserine (DCS) is a partial N-methyl-D-aspartate (NMDA) receptor agonist that may improve or accelerate extinction learning. We will randomly assign people with snake phobia to receive DCS or placebo, and then provide all participants with exposure therapy. We will examine whether people receiving DCS and vs. placebo show different brain reactions to symptom provocation before and after exposure therapy.

Study Timeline

• Study Start: 2010-07
• Study First Submitted: 2011-10-06
• Study First Submitted QC: 2011-10-11
• Study First Posted: 2011-10-12
• Primary Completion: 2011-12
• Study Completion: 2011-12
• Results First Submitted: 2012-05-24
• Results First Submitted QC: 2016-03-25
• Results First Posted: 2016-04-21
• Status Verified: 2024-03
• Last Update Submitted: 2024-03-13
• Last Update Posted: 2024-03-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Primary diagnosis of specific phobia (snakes)

Exclusion Criteria

• History of psychosis, obsessive-compulsive disorder, or mania
• Recent substance abuse or suicidality
• Previous receipt of study treatments

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
D-cycloserine plus exposure therapy	Exposure therapy	Single session (up to 3 hr) of in vivo exposure therapy plus 50 mg oral d-cycloserine administered 1 hr prior to exposure therapy session
Placebo plus exposure therapy	Exposure therapy	Single session (up to 3 hr) of in vivo exposure therapy plus oral placebo capsule administered 1 hr prior to exposure therapy session
Placebo plus exposure therapy	Placebo	Single session (up to 3 hr) of in vivo exposure therapy plus oral placebo capsule administered 1 hr prior to exposure therapy session
D-cycloserine plus exposure therapy	D-cycloserine	Single session (up to 3 hr) of in vivo exposure therapy plus 50 mg oral d-cycloserine administered 1 hr prior to exposure therapy session

Primary Outcome Measures

Name	Time	Method
Snake Questionnaire (SNAQ)	2 weeks	30-item self-report scale of severity of snake fear and avoidance; Range: 0-30; higher values indicate greater fear severity

Secondary Outcome Measures

Name	Time	Method
Clinician's Global Impression (CGI)-Severity	2 weeks	Clinician rating of global illness severity (at pre- and post-treatment); CGI-Severity range 1-7; higher scores indicate greater illness severity.
Clinician's Global Impression (CGI)-Improvement	2 weeks	Clinician rating of global illness severity (at post-treatment); CGI-Improvement range 1-7; higher scores indicate poorer improvement; classified as responder if score = 1 or 2, nonresponder if score \> 2

Trial Locations

Locations (1)

Institute of Living/Hartford Hospital; 🇺🇸 Hartford, Connecticut, United States