Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626000667314
Ethics application status
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Approved
Date submitted
Help: Date submitted
16/05/2025
Date registered
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4/06/2026
Date last updated
Help: Date last updated
4/06/2026
Date data sharing statement initially provided
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4/06/2026
Type of registration
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Retrospectively registered

Titles & IDs
Public title
The Role of Hyperbaric Oxygen Therapy in the Treatment of Ex-Serving Members of the Australian Defence Force Diagnosed With Post-Traumatic Stress Disorder: A Comparative Pressure Intervention Pilot Study
Scientific title
The Role of Hyperbaric Oxygen Therapy in the Treatment of Ex-Serving Members of the Australian Defence Force Diagnosed With Post-Traumatic Stress Disorder: A Comparative Pressure Intervention Pilot Study
Additional trial identifiers [1] 314465 0
None
Universal Trial Number (UTN)
Trial acronym
Related trial records

Health condition
Health condition(s) studied:
Post traumatic stress disorder in Australian veterans 337500 0
Condition category
Condition code
Mental Health 333865 333865 0 0
Other mental health disorders

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
This is an intervention, pilot study looking at the efficacy of hyperbaric oxygen therapy in treating Ex-Serving Members of the Australian Defence Force Diagnosed With Post-Traumatic Stress Disorder, comparing two different pressures 1.5 ATA and 2 ATA.

The participants will be randomly selected into one of two groups: one group completing 60 sessions of 90 minute durations of hyperbaric oxygen therapy (HBOT), 5 days a week for 12 weeks at 2 atmospheres (ATA) of pressure or 1.5 ATA. This will be conducted at a speciaist hyperbaric clinic on the Gold Coast. The intervention will be delivered by trained/qualified nurses and hyperbaric technicians.

They will be required to complete questionnaires prior to the first session around PTSD symptoms, sleep and heart rate variability, after the 30th session, after the last HBOT session and three months after the intervention as a follow up.

Resting state functional MRIs (rsfMRI) will be undertaken before the 1st HBOT session, after the 30th and after the 60th session. These will take place at Mermaid Beach Radiology clinic and will take around 30 minutes.

Adherence to the HBOT intervention will be assessed using prospective session attendance logs. Attendance will be recorded for all scheduled sessions (total n = 60 per participant), including completion status and reasons for missed or incomplete sessions where available. Adherence will be defined a priori as the proportion of prescribed sessions completed per participant.

Intervention fidelity will be ensured through the use of a standardised treatment protocol, including fixed pressure allocation (1.5 ATA or 2.0 ATA), session duration (90 minutes), oxygen delivery parameters, and air break schedules. These parameters will be pre-set and recorded each session. Operator-completed session checklists will be used to confirm protocol delivery, including verification of participant identity, prescribed pressure, session duration, completion of air breaks, and documentation of any deviations or adverse events.

Strategies to support adherence will include appointment reminders (e.g., SMS/email) and flexible scheduling where feasible. Reasons for non-adherence or withdrawal will be recorded to inform feasibility outcomes.
Intervention code [1] 331088 0
Treatment: Devices
Description of the comparator or control
Recent clinical trials in this field (PTSD in veterans) have been conducted at 2 ATA, so this will be the reference comparator in this trial.
Control group
Dose comparison

Outcomes
Primary outcome [1] 341495 0
PTSD symptoms
Timepoint [1] 341495 0
This will be competed before the intervention, immediately after the 30th HBOT session, within 48 hours after the completion of the last HBOT session (60th), and 3 months after the last (60th) HBOT session.
Primary outcome [2] 345207 0
Depression symptoms
Timepoint [2] 345207 0
This will be competed before the intervention, immediately after the 30th HBOT session, within 48 hours after the completion of the last HBOT session (60th), and 3 months after the last (60th) HBOT session
Primary outcome [3] 345208 0
Sleep quality
Timepoint [3] 345208 0
This will be competed before the intervention, immediately after the 30th HBOT session, within 48 hours after the completion of the last HBOT session (60th), and 3 months after the last (60th) HBOT session
Secondary outcome [1] 447776 0
changes in functional connectivity and activity within brain networks. This will be assessed as a composite outcome.
Timepoint [1] 447776 0
this will be competed before the first hyperbaric oxygen session, immediately after the 30th and immediately after the 60th HBOT session
Secondary outcome [2] 460973 0
subjective awareness of bodily sensations and perceived autonomic nervous system (ANS) reactivity across systems such as cardiovascular, respiratory, and gastrointestinal function. This will be assessed as a composite outcome.
Timepoint [2] 460973 0
This will be competed before the intervention, immediately after the 30th HBOT session, within 48 hours after the completion of the last HBOT session (60th), and 3 months after the last (60th) HBOT session

Eligibility
Key inclusion criteria
• Ex-Serving Members of the Australian Defence Force Diagnosed With Post-Traumatic Stress Disorder by the subject’s healthcare practitioner using the Clinician-Administered PTSD Scale (CAPS) or similar. The questionnaire has 30 questions and includes both the diagnostic criteria for PTSD as well as questions about the severity and frequency of symptoms.
• Between the ages of 25-60
• Women and men
Minimum age
25 Years
Maximum age
60 Years
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
• Unstable medical conditions, such as a serious brain injury, serious heart condition, pneumothorax (to be screened with chest X-ray), neurological disorder, cancer or seizure disorder
• Currently pregnant or lactating
• Have current substance abuse
• Previous HBOT treatment
• Ear or sinus pathologies incompatible with pressure changes such as severe sinusitis, pharyngitis or otitis media
• No planned major surgical procedures planned during the timeframe of the study
• cognitive impairment, an intellectual disability, or a mental illness

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)
Allocation concealment will be done by central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation will be employed using a randomisation table created by computer software (www.randomizer.org)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
As regards the pilot study nature of the current study, the generally accepted size is 12 participants per group, which allows for balance between precision and feasibility for data to be used in future trials (Julious, 2005). Previous studies for HBOT for PTSD in veterans have shown a 15% dropout rate of participants (Doenyas-Barak et al., 2022), so the goal of recruitment will be 15 per group and a total of 30 for the study to allow for a 15% drop out rate (potentially resulting in 12 per group).

Analysis:
• Primary analyses of the feasibility data will be descriptive, reporting counts, proportions, means with standard deviations, or medians with interquartile ranges, together with 95 percent confidence intervals.
• Psychological questionnaire scores will be analysed using paired-samples t-tests or repeated measures ANOVA to assess within-subject changes over time.
• Subgroup or between-group comparisons (e.g., based on HBOT pressure level or baseline severity) will be analysed using mixed-model ANOVAs or ANCOVAs where relevant.
• fMRI data will be pre-processed and analysed using standard neuroimaging software (e.g., SPM, CONN toolbox). Analysis will include seed-to-voxel or region-of-interest (ROI) approaches to examine connectivity changes in brain regions relevant to PTSD (e.g., amygdala, hippocampus, medial prefrontal cortex).
• Correlational analyses will be conducted to explore associations between changes in psychological outcomes and neuroimaging measures.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
27/02/2026
Date of last participant enrolment
Anticipated
21/12/2026
Actual
Date of last data collection
Anticipated
26/03/2027
Actual
Sample size
Target
30
Accrual to date
16
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 319002 0
University
Name [1] 319002 0
Bond University
Country [1] 319002 0
Australia
Funding source category [2] 321839 0
Self funded/Unfunded
Name [2] 321839 0
Nicholas Bradley, Hyperbaric O2 Gold Coast
Country [2] 321839 0
Australia
Primary sponsor type
University
Name
Bond University
Address
Country
Australia
Secondary sponsor category [1] 324922 0
None
Name [1] 324922 0
Address [1] 324922 0
Country [1] 324922 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 317615 0
Bond University Human Research Ethics Committee
Ethics committee address [1] 317615 0
Ethics committee country [1] 317615 0
Australia
Date submitted for ethics approval [1] 317615 0
16/05/2025
Approval date [1] 317615 0
20/10/2025
Ethics approval number [1] 317615 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 141574 0
Mr Nicholas Bradley
Address 141574 0
Hyperbaric O2 Gold Coast, 86 Quambone street, Worongary, QLD, 4213
Country 141574 0
Australia
Phone 141574 0
+61448491805
Fax 141574 0
Email 141574 0
[email protected]
Contact person for public queries
Name 141575 0
Nicholas Bradley
Address 141575 0
Hyperbaric O2 Gold Coast, 86 Quambone street, Worongary, QLD, 4213
Country 141575 0
Australia
Phone 141575 0
+61448491805
Fax 141575 0
Email 141575 0
[email protected]
Contact person for scientific queries
Name 141576 0
Nicholas Bradley
Address 141576 0
Hyperbaric O2 Gold Coast, 86 Quambone street, Worongary, QLD, 4213
Country 141576 0
Australia
Phone 141576 0
+61448491805
Fax 141576 0
Email 141576 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


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.