Generalization of Extinction Learning

October 3, 2019 updated by: Michelle Craske, University of California, Los Angeles

Cholinergic Decontextualization of Exposure Therapy for Anxiety

Fear, whether it occurs in humans suffering from an anxiety disorder or in experimental models with rodents, is reduced by exposing the frightened organism to the fearful stimulus in the absence of any negative consequences (i.e., extinction, or exposure therapy). However, fear often renews when the feared stimulus is encountered in a context different from the exposure context. In rats, the investigators found that interfering with the animal's ability to process contexts during extinction by administering an anticholinergic drug prevented fear renewal. This proposal will determine if the beneficial effect of this drug translates to exposure therapy in socially anxious humans. To this end, 100 individuals with Social Phobia who fear public speaking will undergo repeated sessions of exposure to public speaking, within a virtual reality context. Participants will be randomized to either drug placebo, .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy. One month after completion of exposure therapy, context renewal will be tested by comparing physiological and subjective responses to public speaking in the same virtual context as used during exposure therapy versus a context different than the one used during exposure therapy. The goal is to identify the dose of Scopolamine associated with the greatest reduction in context renewal. In addition, a secondary analysis will attempt to identify those individuals who benefit most from Scopolamine-augmentation of exposure therapy.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • California
      • Los Angeles, California, United States, 90095
        • University of California, Los Angeles

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years to 51 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. between the ages of 18 and 55,
  2. fluent in English,
  3. within normal body weight (BMI=18.5 to 24.9)
  4. meet DSM-IV diagnostic criteria for Social Phobia and report a fear of public speaking.

Exclusion Criteria:

  1. participant report of a diagnosed medical or neurological disorder
  2. prescription or over the counter medications that can interact with Scopolamine, such as anticholinergic medications (e.g. belladonna alkaloids, antihistamines, meclizine, tricyclic antidepressants, and muscle relaxants), cold medicines, cough suppressants. Other drugs that will be reasons for exclusion include: antimuscarinics, nifedipine, parasympathomimetics, amantadine, amoxapine, antacids, antidiarrheals, anxiolytics, hypnotics, atomexetine, bupropion, cisapride, clozapine, cyclobenzaprine, digoxin, disopyramide, dronabinol (THC), ethanol, maprotilline, memantine, metoclopramide, nabilone, olanzapine, opiate agonists, orphenadrine, phenothiazines, potassium salts, quinidine, sedating H1-blockers, topiramate, tricyclic antidepressants, erthyromycin, ketoconazole, and tegaserod.
  3. over the counter drugs or substances that may have a sedative effect (e.g. herbal sedatives: ashwagandha, Duboisia hopwoodii, Prostanthera striatiflora, kava, mandrake, valerian, cannabis, passiflora incarnate; Antihistamines: Diphenhydramine, Dimenhydrinate, Doxylamine, Promethazine; Alcohol; Dextromethorphan)
  4. individuals with urinary problems (e.g., BPH)
  5. pregnant or nursing females (as the effect of Scop on fetuses is not known)
  6. suicidality
  7. delusions or hallucinations
  8. history of substance dependence in last five years or substance abuse within the past 6 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Scopolamine .4mg
Participants will be randomized to either .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy
Participants will be randomized to either, .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy
Placebo Comparator: Intranasal placebo
Participants will be randomized to a placebo, administered via nasal drops, prior to each session of exposure therapy
Participants will be randomized to a drug placebo, administered via nasal drops, prior to each session of exposure therapy
Experimental: Scopolamine .5mg
Participants will be randomized to either .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy
Participants will be randomized to either, .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy
Experimental: Scopolamine .6mg
Participants will be randomized to either .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy
Participants will be randomized to either, .4mg/.01 mL Scopolamine, .5mg/.01 mL Scopolamine or .6mg/.01 mL Scopolamine, administered via nasal drops, prior to each session of exposure therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Eye blink startle reflex
Time Frame: change from final exposure session to follow-up (8 weeks following baseline)
change from final exposure session to follow-up (8 weeks following baseline)
Skin conductance responses and heart rate
Time Frame: change from final exposure session to follow-up (8 weeks following baseline)
change from final exposure session to follow-up (8 weeks following baseline)
Subjective Units of Distress
Time Frame: change from final exposure session to follow-up (8 weeks following baseline)
change from final exposure session to follow-up (8 weeks following baseline)

Secondary Outcome Measures

Outcome Measure
Time Frame
Self Statements During Public Speaking Scale
Time Frame: change from baseline to follow-up (8 weeks following baseline)
change from baseline to follow-up (8 weeks following baseline)
Personal Report of Confidence as a Speaker Scale
Time Frame: change from baseline to follow-up (8 weeks following baseline)
change from baseline to follow-up (8 weeks following baseline)
Subjective units of distress during in vivo speech
Time Frame: change from baseline to follow-up (8 weeks following baseline)
change from baseline to follow-up (8 weeks following baseline)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Michelle G. Craske, Ph.D., Department of Psychology, UCLA
  • Principal Investigator: Michael Fanselow, Ph.D., Department of Psychology, UCLA

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2013

Primary Completion (Actual)

August 1, 2017

Study Completion (Actual)

August 1, 2017

Study Registration Dates

First Submitted

July 8, 2013

First Submitted That Met QC Criteria

July 11, 2013

First Posted (Estimate)

July 16, 2013

Study Record Updates

Last Update Posted (Actual)

October 7, 2019

Last Update Submitted That Met QC Criteria

October 3, 2019

Last Verified

October 1, 2019

More Information

Terms related to this study

Other Study ID Numbers

  • MH101359-01

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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