ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12610000587000

Ethics application status

Not yet submitted

Date submitted

13/07/2010

Date registered

21/07/2010

Date last updated

21/07/2010

Type of registration

Prospectively registered

Titles & IDs

Public title

Treatment for public speaking fears

Scientific title

The effect of D-Cycloserine on imaginal and in-vivo exposure therapy for public speaking anxiety

Secondary ID [1]

Nil

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Public speaking anxiety

Condition category

Condition code

Mental Health

Anxiety

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

The study will consist of 5 experimental treatment sessions scheduled at weekly intervals on an individual basis for participants in the imaginal exposure therapy conditions, and group basis for participants in the in-vivo exposure therapy conditions. Participants will be randomly assigned to one of the following conditions: Imaginal exposure therapy + D-Cycloserine (DCS), Imaginal exposure therapy + placebo, In-vivo exposure therapy + DCS, or In-vivo exposure therapy + placebo. Participants will be assigned to groups using random block assignment. Prior to the commencement of treatment, and after the completion of treatment, all participants will be asked to give a 3 minute impromptu speech on a topic of their choice. Participants will given 2 minutes to prepare their speech and will be videotaped.

Imaginal Exposure Treatment -

Treatment session 1 will consist of psycho-education about imaginal exposure therapy and treatment (60 minutes). Placebo and DCS tablets will be made into two different colours by the compounding chemist. At the beginning of treatment session 2 participants will be asked to toss a coin. How the coin lands will determine what colour tablet the participant will take. Neither the co-investigator nor the participant will know which tablet they will be taking. The participants will then take the same capsule (500mg) before each exposure session. In the imaginal exposure therapy condition participants will be asked by the therapist to imagine themselves giving a speech about a topic of their choice. Participants will be given a list of topics from which to choose. Consistent with previous studies using exposure each session will consist of three exposure tasks (i.e. three speeches), each of which will be 5 minutes in duration, with a total of 15 minutes of exposure per session. The speeches will become increasingly difficult as the sessions progress.

In-Vivo Treatment -

As with imaginal exposure, treatment session 1 will consist of psycho-education about in-vivo exposure and treatment (60 minutes). Allocation of capsules to participants will be determined in the same manner as in the imaginal exposure condition, and participants will be required to take the same capsule (500mg) before each exposure session. In the in-vivo exposure therapy condition participants will be asked by the therapist to give a speech about a topic of their choice. Each session will consist of three exposure tasks (i.e. three speeches), each of which will be 5 minutes in duration, with a total of 15 minutes of exposure per participant in each session. The audience will consist of 4 participants who will also be giving 3 speeches within the same session in turn. Each exposure session will be 90 minutes in duration in total. The speeches will become increasingly difficult as the sessions progress and all sessions will be video recorded.

Intervention code [1]

Treatment: Drugs

Intervention code [2]

Behaviour

Comparator / control treatment

The 500 mg placebo tablet will contain sugar. Apart from colour, it will look identical to the DCS tablet, without the active ingredients.

Control group

Placebo

Outcomes

Primary outcome [1]

Reductions in anxiety as measured by the Depression Anxiety Stress Scale (DASS-21), Shortened version of the Social Phobia Scale (SPS), Social Interaction Anxiety Scale (SIAS), and Personal Report of Communication Apprehension (PRCA-24)

Timepoint [1]

Prior to the commencement of treatment, and after treatment has been completed (treatment = 5 weeks duration)

Secondary outcome [1]

Improvement in public speaking competency as measured by the Personal Report of Confidence as a Speaker (PRCS)

Timepoint [1]

Prior to the commencement of treatment, and after treatment has been completed (treatment = 5 weeks duration)

Eligibility

Key inclusion criteria

To be eligible for participation in the study, individuals will be required to score 16 or above on the Personal Report of Confidence as a Speaker (PRCS) and 80 or above on the Personal Report of Communication Apprehension (PRCA). Participants will be given written information outlining the study and written consent will be required before individuals can participate

Minimum age

18 Years

Maximum age

65 Years

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

Consistent with previous research the exclusion criteria for participation in the study will be a diagnosis of major depression, bipolar disorder, psychotic symptoms, kidney disease, epilepsy, pregnancy or intention to become pregnant, substance dependence and participation in other psychological treatments. Participants will be advised to cease caffeine, nicotine and alcohol consumption on the days they are attending treatment sessions

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Masking / blinding

Who is / are masked / blinded?

Intervention assignment

Other design features

Phase

Phase 4

Type of endpoint/s

Statistical methods / analysis

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

14/09/2010

Actual

Date of last participant enrolment

Anticipated

Actual

Date of last data collection

Anticipated

Actual

Sample size

Target

140

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

Funding & Sponsors

Funding source category [1]

University

Name [1]

Macquarie University

Address [1]

Department of Psychology Macquarie University NSW 2109

Country [1]

Australia

Primary sponsor type

University

Name

Macquarie University

Address

Department of Psychology
Macquarie University
NSW 2109

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Not yet submitted

Ethics committee name [1]

Ethics committee address [1]

Ethics committee country [1]

Date submitted for ethics approval [1]

25/06/2010

Approval date [1]

Ethics approval number [1]

Summary

Brief summary

D-cycloserine (DCS) is an antibiotic that has been used for the treatment of Tuberculosis over the last 40 years. Research indicates that DCS affects receptors in the brain known as N-methyl-D-aspartate (NMDA) receptors which are located in a region of the brain called the Amygdala. When the NMDA receptors become active (as occurs during extinction) this leads to a reduction in fear levels. Research suggests that DCS enhances the activity of these receptors, and as a result, enhances therapy techniques such as exposure (Guastella, Lovibond, Dadds, Mitchell & Richardson, 2007). 

To date, few studies have investigated the effects of DCS as an adjunct to exposure therapy using human participants, and of these none have done so using imaginal exposure therapy. The research thus far has focused primarily on the effects of DCS with in-vivo exposure on individuals. Yet, the same underlying processes appear to contribute to the success of both imaginal and in-vivo exposure therapy, i.e. the activation of anxiety and the formation of new associations in the brain through confrontation of the feared stimulus or situation. If DCS works by strengthening the formation or accessibility of new, non-threat associations (Guastella, Richardson, Lovibond, Rapee, Gaston, Mitchell & Dadds  2008), then it should also enhance the effects of imaginal exposure. Therefore there is good theoretical reason to see whether DCS has the same exposure enhancing properties when used as an adjunct to imaginal exposure therapy. In terms of its application in clinical settings, imaginal exposure therapy has several advantages compared to in-vivo exposure techniques, offering greater practicality and flexibility, particularly with regards to situations that are not readily accessible. Research also suggests that individuals experience less aversion when exposed to fearful images than when they are in direct contact with the feared object or situation (Hunt, Bylsma, Brock, Fenton, Goldberg, Miller, Tran & Urgelles, 2006). This relatively novel area of research has the potential to revolutionise the practice of psychotherapy and possibly offer new treatment options to individuals with public speaking anxiety and possibly other anxiety disorders. 

Aims of the study - 


1. To replicate previous research which shows that DCS enhances in-vivo exposure therapy for individuals with public speaking anxiety

2. To extend previous research by showing that DCS enhances imaginal exposure therapy for individuals with public speaking anxiety

3. To determine whether the ability to conjure up a vivid image and become absorbed in that image increases anxiety levels as measured by self-report and physiological changes, and in turn, leads to positive treatment outcome

4. To determine whether competency in public speaking improves as treatment progresses

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Address

Country

Phone

Fax

Contact person for public queries

Name

Natasha Galovic

Address

Department of Psychology Macquarie University NSW 2109

Country

Australia

Phone

+61 (0)401 965 440

Fax

[email protected]

Contact person for scientific queries

Name

Professor Ron Rapee

Address

Department of Psychology Macquarie University NSW 2109

Country

Australia

Phone

+61 2 9850 8032

Fax

[email protected]

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically