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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] 252205 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Public speaking anxiety 257736 0
Condition category
Condition code
Mental Health 257910 257910 0 0
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] 256798 0
Treatment: Drugs
Intervention code [2] 256799 0
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] 258771 0
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] 258771 0
Prior to the commencement of treatment, and after treatment has been completed (treatment = 5 weeks duration)
Secondary outcome [1] 264831 0
Improvement in public speaking competency as measured by the Personal Report of Confidence as a Speaker (PRCS)
Timepoint [1] 264831 0
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?
No
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] 257280 0
University
Name [1] 257280 0
Macquarie University
Country [1] 257280 0
Australia
Primary sponsor type
University
Name
Macquarie University
Address
Department of Psychology
Macquarie University
NSW 2109
Country
Australia
Secondary sponsor category [1] 256523 0
None
Name [1] 256523 0
Address [1] 256523 0
Country [1] 256523 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 259305 0
Ethics committee address [1] 259305 0
Ethics committee country [1] 259305 0
Date submitted for ethics approval [1] 259305 0
25/06/2010
Approval date [1] 259305 0
Ethics approval number [1] 259305 0

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 31388 0
Address 31388 0
Country 31388 0
Phone 31388 0
Fax 31388 0
Email 31388 0
Contact person for public queries
Name 14635 0
Natasha Galovic
Address 14635 0
Department of Psychology
Macquarie University
NSW 2109
Country 14635 0
Australia
Phone 14635 0
+61 (0)401 965 440
Fax 14635 0
Email 14635 0
[email protected]
Contact person for scientific queries
Name 5563 0
Professor Ron Rapee
Address 5563 0
Department of Psychology
Macquarie University
NSW 2109
Country 5563 0
Australia
Phone 5563 0
+61 2 9850 8032
Fax 5563 0
Email 5563 0
[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
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