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Trial registered on ANZCTR


Registration number
ACTRN12620000558921p
Ethics application status
Submitted, not yet approved
Date submitted
16/04/2020
Date registered
13/05/2020
Date last updated
13/05/2020
Date data sharing statement initially provided
13/05/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Using mild non-invasive brain stimulation for identifying and targeting brain-based changes in anxiety.
Scientific title
Identifying and Targeting Brain Correlates of Anxiety using Electroencephalogram and Transcranial Alternating Current Stimulation (tACS) in individuals with either low or high trait anxiety
Secondary ID [1] 301004 0
Nil known
Universal Trial Number (UTN)
U1111-1250-4135
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anxiety 317042 0
Condition category
Condition code
Mental Health 315206 315206 0 0
Anxiety
Mental Health 315207 315207 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This study will take place across 3 sessions, with the 2nd and 3rd session following a cross-over design. An interval of at least 72 hours will be mandatory between the two transcranial alternating current stimulation (tACS) sessions to ensure no carry-over effects of stimulation. All three sessions will be conducted within 3 months’ time from the first session.
Session 1 outline (duration: approximately 2.5-3 hours)
Baseline characterization of participants.
Including:
Relevant demographic and health-related information: i.e. age, gender, education, current diagnoses and any medication or treatment they are currently receiving.
Cognition: this will involve a cognitive battery of tests that will include: Forward and Backward Digit Span test, Trail Making Test (TMT), Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test Revised (BVMT-R), Rey Auditory Verbal Learning Test (RAVLT) and F-A-S test.
Measure of clinical anxiety severity (Beck Anxiety Inventory).
Measure of depression severity (Beck Depression Inventory); given the high co-morbidity between depression and anxiety.
This will also include a participants undergoing EEG, including resting EEG, and task-related EEG during two attentional control tasks: the Classical Stroop Task and the Emotionally-Modified Stroop task. Stroop task type order will be randomized and counterbalanced. Comparing the task-related EEG and Stroop reaction time results is a secondary aim of the study, examining differences in emotional and non-emotional attentional control. The cognitive battery and measures of clinical anxiety and depression severity are to be used as a baseline characterization of participant groups.

This will be followed by randomized and counterbalanced sequence of two sessions of tACS conducted at least 72 hours apart, each approximately (1-1.5 hours in duration) with details as follows:
1) 2 x 8 minutes blocks of tACS set at an individualized theta frequency and individualized intensity applied bilaterally to the left and right dorsolateral prefrontal cortex (DLPFC) during an attentional control task (the dot-probe) with resting EEG, state anxiety levels (measured with STAI-6) and alertness/arousal (measured on a 10-point visual analogue scale) measured pre- and post- stimulation.
2) 2 x 8 minutes blocks of sham (placebo) tACS with 30 seconds 'fade in' to a participant's individualized intensity and frequency followed by an immediate 30 seconds 'fade out' (i.e. zero stimulation) applied bilaterally to the left and right DLPFC during an attentional control task (the dot-probe) with resting EEG, state anxiety levels (measured with STAI-6) and alertness/arousal (measured on a 10-point visual analogue scale) measured pre- and post- stimulation.

Note regarding individualization: An algorithm will be used to determine a participant’s individual theta frequency during resting EEG prior to active/sham tACS, which will then be the frequency that participant will be stimulated with. If the algorithm is not able to clearly identify a peak frequency, which can occur, default stimulation will be set at a frequency of 6 Hz. After determining individualized theta frequency, intensity i.e. the amount of mA will be determined for each individual by the method of perceptual thresholding. This is where the intensity i.e. mA is increased until the participant sees phosphenes (flashing lights), then the amount of mA is set just below this level. This is a common method used in tACS studies. Stimulation intensity will not exceed 2.0mA.

All data collection (baseline measures, attentional control tasks and resting and task-related EEG) and tACS administration is to be conducted by Jessica Michael (PhD candidate) at the Epworth Centre for Innovation in Mental Health.

Intervention code [1] 317323 0
Treatment: Devices
Comparator / control treatment
2 x 8 minutes blocks of sham (placebo) tACS with 30 seconds 'ramping up' to a participant's individualized intensity and frequency followed by an immediate 30 seconds 'ramping down' (i.e. to zero stimulation) applied bilaterally to the left and right DLPFC during an attentional control task (the dot-probe) with resting EEG. State anxiety levels (measured with STAI-6) and alertness/arousal (measured on a 10-point visual analogue scale) will be measured pre- and post- stimulation.
This sham (placebo) stimulation will improve blinding by causing the characteristic scalp sensations, while not eliciting significant biological effects in proximity to experimental task completion.
Levels of state anxiety, alertness/arousal, dot-probe results and resting EEG power measures will be compared pre- and post-tACS across the two groups (active and placebo tACS).
Control group
Placebo

Outcomes
Primary outcome [1] 323464 0
Changes in resting power EEG
Timepoint [1] 323464 0
Pre- and post- active/sham tACS (in-session)
Primary outcome [2] 323466 0
Reaction time scores on dot-probe task
Timepoint [2] 323466 0
During active/sham tACS
Primary outcome [3] 323467 0
Level of State Anxiety (measured with STAI-6)
Timepoint [3] 323467 0
Pre- and post- active/sham tACS (in session)
Secondary outcome [1] 382507 0
Alertness/arousal (measured on a 10-point visual analogue scale)
Timepoint [1] 382507 0
Measured pre- and post- active/sham tACS.

Eligibility
Key inclusion criteria
Right-handed (according to Edinburgh Handedness Inventory).
18-65 years old.
Participants will be selected for based on their score of the trait-anxiety subscale of the State-Trait-anxiety Inventory (STAI),:
Low trait-anxiety group: score less than or equal to 28 OR
High trait-anxiety group: score greater than or equal to 40.
STAI trait subscale scores range from 20 to 80. These cut-off scores were chosen as they represent the top and bottom 25% of scores for healthy adults according to percentile ranking in the STAI manual.
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Low trait-anxiety group only: Diagnosis of an anxiety disorder or any other metal health disorder.
High trait-anxiety group only: Diagnosis of any mental health disorder EXCEPT those with a diagnosis of social anxiety disorder and/or generalized anxiety disorder and/or a specific phobia.
For both groups:
Metal inside the head (excluding dental work) or a pacemaker, cochlear implant, medication pump or other electronic device within the body.
Currently taking any psychotropic medication e.g. antidepressants
Medical history of; or current neurological disorder.
Unstable medical illness.
Any history of significant head injury or traumatic brain injury, as defined by a loss of consciousness greater than 30 minutes or requiring a hospital admission.
Pregnancy or breastfeeding.
Uncorrected visual or hearing impairment, including colour perception.
Significant difficulties with English communication and comprehension.

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)
Device condition is coded; central randomisation by computer.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 305448 0
University
Name [1] 305448 0
Monash University
Address [1] 305448 0
Wellington Road,
Clayton, Victoria, 3800
Country [1] 305448 0
Australia
Primary sponsor type
University
Name
Monash University
Address
Wellington Road,
Clayton, Victoria, 3800
Country
Australia
Secondary sponsor category [1] 305847 0
Hospital
Name [1] 305847 0
Epworth Centre for Innovation in Mental Health, Epworth Healthcare
Address [1] 305847 0
888 Toorak Road,
Camberwell, Victoria, 3124
Country [1] 305847 0
Australia

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 305765 0
Monash Health Human Research Ethics Committee
Ethics committee address [1] 305765 0
246 Clayton Road,
Clayton, VIC 3168
Ethics committee country [1] 305765 0
Australia
Date submitted for ethics approval [1] 305765 0
05/03/2020
Approval date [1] 305765 0
Ethics approval number [1] 305765 0

Summary
Brief summary
Up to 33.7% of the population will have a diagnosis of an anxiety disorder throughout their lifetime and current treatment approaches are largely ineffective; having moderate effects at best. However, given the substantial economic and personal burden of anxiety new treatments are urgently needed. This project aims to explore a different approach to anxiety: transcranial alternating current stimulation (tACS). tACS is a mild form of non-invasive brain stimulation. This study aims to use tACS to target some brain-based changes found in individuals with anxiety, with the aim of helping to reduce feelings of anxiety in these individuals.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 101518 0
A/Prof Kate Hoy
Address 101518 0
Monash University,
Epworth Centre for Innovation in Mental Health,
888 Toorak Road,
Camberwell, Victoria, 3124
Country 101518 0
Australia
Phone 101518 0
+61 3 9805 4186
Fax 101518 0
Email 101518 0
jessica.michael1@monash.edu
Contact person for public queries
Name 101519 0
Ms Jessica Michael
Address 101519 0
Monash University,
Epworth Centre for Innovation in Mental Health,
888 Toorak Road,
Camberwell, Victoria, 3124
Country 101519 0
Australia
Phone 101519 0
+61 3 9805 4163
Fax 101519 0
Email 101519 0
kate.hoy@monash.edu
Contact person for scientific queries
Name 101520 0
A/Prof Kate Hoy
Address 101520 0
Monash University,
Epworth Centre for Innovation in Mental Health,
888 Toorak Road,
Camberwell, Victoria, 3124
Country 101520 0
Australia
Phone 101520 0
+61 3 9805 4186
Fax 101520 0
Email 101520 0
kate.hoy@monash.edu

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
All data collected throughout the trial: Group-level participant de-identified data, unidentifiable meta-data
When will data be available (start and end dates)?
Group level participant de-identified data will be available if and when required as part of publishing the results. Outside of these circumstances, then data will be available January 2023 (i.e. the expected conclusion of the project, where unidentifiable meta-data will be accessible through the Monash University Research Repository).
Available to whom?
Researchers who agree to preserve the confidentiality of the data, provide information regarding the proposed use of the data, and pending approval from the original research team.
Available for what types of analyses?
As approved by the original research team.
How or where can data be obtained?
Access subject to approval by the original research team, by emailing principal investigator kate.hoy@monash.edu, including through provision to the Monash University Research Repository, a regulated online database, dependent on participant consent for re-use of data.
What supporting documents are/will be available?
No other documents available
Summary results
No Results