Trial Review

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12625001126404
Ethics application status
Help: Ethics application status
Approved
Date submitted
Help: Date submitted
16/09/2025
Date registered
Help: Date registered
15/10/2025
Date last updated
Help: Date last updated
15/10/2025
Date data sharing statement initially provided
Help: Data sharing statement date
15/10/2025
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
Efficacy of Varying Formats of Cognitive Processing Therapy (CPT) for posttraumatic stress disorder (PTSD): An open trial.
Scientific title
Impact of Varying Formats of Cognitive Processing Therapy (CPT) on PTSD symptom severity in adults: An open trial.
Additional trial identifiers [1] 315242 0
nil known
Universal Trial Number (UTN)
Trial acronym
Related trial records

Health condition
Health condition(s) studied:
Post Traumatic Stress Disorder (PTSD) 338700 0
Condition category
Condition code
Mental Health 334985 334985 0 0
Other mental health disorders

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Cognitive Processing Therapy (CPT) will be offered in four different formats. 1) self-help, 2) guided self-help, 3) abbreviated CPT protocol, 4) standard CPT protocol. Australian and international guidelines consistently have listed Cognitive Processing Therapy (CPT) as a recommended, manualised treatment for PTSD. CPT typically consists of 12 sessions that focus on examining the unhelpful cognitions surrounding a traumatic event (i.e., “stuck points”). The modules each focus on a different topic (e.g., education about PTSD, the link between events, thoughts and emotions) and teach clients to examine their unhelpful thoughts and beliefs through a range of worksheets. CPT can be used in a range of different formats (e.g., standard, telehealth, face-to-face, online modules, self-help book).

The present study is a pragmatic open trial in which clients can choose between four formats of Cognitive Processing Therapy. All four formats cover the same content (as described above), it is just delivered with varied therapist input and varied duration. Namely, (1) self-help CPT, (2) guided self-help CPT, (3) CPT over 8 sessions [CPT-8], and (4) CPT over 12 sessions [CPT-12].

In format (1), self-help, you receive a self-help manual that guides you through weekly exercises to complete it and you will complete a brief weekly questionnaire to check your progress. It is anticipated it will take approximately 12- weeks to complete and has minimal therapist input.

In format (2), guided self-help, you will be given weekly 60-minute modules (pdf workbooks) and practise exercises to complete. You will receive weekly feedback from your therapist via email on your progress and exercises.

Format (3) and (4) consist of weekly 60 minutes sessions either face-to-face or via telehealth.

As a part of the current study, in consultation with your therapist, you can choose during therapy to move to another format (e.g., to move from guided self-help to CPT-8, or move from CPT-12 down to CPT-8). There might also be occasions where the therapist will discuss moving into another format if you are not noticing improvements. Clients are eligible for a maximum of 18 sessions across CPT formats, which would take approximately 18 weeks post enrolment.

Participants will be screened to ensure eligibility, and once enrolled, will complete assessments at baseline, 2 weeks post treatment and at 3 months post-treatment, as well as brief measures weekly. Session attendance checklists and homework completion will be logged per client throughout treatment.

Therapists involved are either registered psychologists or currently undertaking clinical psychology training. All therapists will have training in the CPT protocol and receive weekly supervision from the chief investigator (clinical psychologist).
Intervention code [1] 331852 0
Treatment: Other
Intervention code [2] 332061 0
Behaviour
Description of the comparator or control
The study is an open trial with no control group.

CPT formats are unlikely to be directly compared with each other due to low sample size. However, should two formats have sufficient data available exploratory analysis may be conducted.

The reduction in individual participants' pre- and post- treatment scores and associated effect sizes will be calculated and compared with that seen in past research.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 342612 0
Change in PTSD symptom severity.
Timepoint [1] 342612 0
Pretreatment, posttreatment (2-weeks following CPT completion or CPT disengagement), 3-month follow-up (3-months following CPT completion or CPT disengagement).
Primary outcome [2] 342613 0
Proportion of participants who no longer meet the DSM-5 diagnostic criteria for PTSD
Timepoint [2] 342613 0
Pretreatment, posttreatment (2-weeks following CPT completion or CPT disengagement), 3-month follow-up (3-months following CPT completion or CPT disengagement).
Primary outcome [3] 342752 0
Disengagement Rate
Timepoint [3] 342752 0
Disengagement will be documented at the point participant ceases therapy. Overall disengagement rate will be calculated at the end of the project.
Secondary outcome [1] 451544 0
Depression
Timepoint [1] 451544 0
Pretreatment, weekly during treatment, posttreatment (2-weeks following CPT completion or CPT disengagement), 3-month follow-up (3-months following CPT completion or CPT disengagement).
Secondary outcome [2] 451563 0
Changes in PTSD symptom severity (weekly)
Timepoint [2] 451563 0
Weekly during course of treatment. CPT treatment ranges from 8 - 18 weeks in the present study.
Secondary outcome [3] 451989 0
Weekly wellbeing
Timepoint [3] 451989 0
Weekly during course of treatment. CPT treatment ranges from 8 - 18 weeks in the present study.
Secondary outcome [4] 452164 0
Cost
Timepoint [4] 452164 0
At study completion
Secondary outcome [5] 452508 0
Psychological distress
Timepoint [5] 452508 0
Pretreatment, weekly during treatment, posttreatment (2-weeks following CPT completion or CPT disengagement), 3-month follow-up (3-months following CPT completion or CPT disengagement).
Secondary outcome [6] 452509 0
Subjective belief in the credibility of treatment and expectation for change
Timepoint [6] 452509 0
After first session and posttreatment (2-weeks following CPT completion or CPT disengagement). Note. self-help group does not complete this measure due to self-paced nature of treatment.
Secondary outcome [7] 452510 0
Therapeutic alliance
Timepoint [7] 452510 0
BR-WAI every 4th session and posttreatment (2-weeks following CPT completion or CPT disengagement). Note. self-help group does not complete this measure due to self-paced nature of treatment.
Secondary outcome [8] 453216 0
Weekly satisfaction with treatment
Timepoint [8] 453216 0
Weekly during course of treatment. CPT treatment ranges from 8 - 18 weeks in the present study.

Eligibility
Key inclusion criteria
All participants must be over 18 years of age and have been directly or indirectly exposed (through witnessing) to a traumatic event (e.g. assault, motor vehicle accident, homicide etc.) four or more weeks prior to inclusion in the study and have met criteria for PTSD (full or subthreshold).
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
Yes
Key exclusion criteria
Exclusion criteria includes individuals with moderate to severe traumatic brain injury, individuals with unmanaged psychosis or current substance dependence, those with a
significant risk of harm (e.g. in a current domestic violence situation) or those with active
suicidality.

Exclusion criteria are on the basis that the nature of the therapy (cognitive behavioural techniques) requires a level of cognition and functioning that enables active participation in therapy, thus higher levels of traumatic brain injury are excluded. Unmanaged substance abuse or psychosis are also exclusions for treatment, given the nature of the therapy and the need for these issues to be managed either concurrently or before treatment occurs. The rationale for the exclusion of participants who are at significant risk of harm reflects that if someone is in imminent danger, or is a danger to themselves or others, then treatment of PTSD should not be the most immediate treatment goal.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised 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
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Linear mixed modelling (LMM) will be used to evaluate treatment effects between pre, post and 3-month follow ups. Chi-square will be used to analyse dichotomous outcomes, analysis of variance (ANOVA) and/or independent sample t-tests will be used to measure cost-effectiveness, treatment credibility and other non-symptom outcomes. Reliability of change analyses (RCI) using established clinical cut-off scores on PTSD and depression measures will be undertaken to document individual treatment changes (including determining remission status).

Confounding is possible given the lack of control groups. However, feasibility studies are important first steps in establishing the feasibility and acceptability of new treatment approaches, which is the goal of the current project. Should the study be successful, larger
treatment trials can begin to include control groups and control for potential confounding
factors.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
27/10/2025
Actual
Date of last participant enrolment
Anticipated
31/07/2026
Actual
Date of last data collection
Anticipated
2/11/2026
Actual
Sample size
Target
25
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 319809 0
University
Name [1] 319809 0
Flinders University College of Education, Psychology and Social Work
Country [1] 319809 0
Australia
Primary sponsor type
University
Name
Flinders University College of Education, Psychology and Social Work
Address
Country
Australia
Secondary sponsor category [1] 322327 0
None
Name [1] 322327 0
NA
Address [1] 322327 0
Country [1] 322327 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 318365 0
Southern Adelaide Clinical Human Research Ethics Committee
Ethics committee address [1] 318365 0
Ethics committee country [1] 318365 0
Australia
Date submitted for ethics approval [1] 318365 0
24/06/2025
Approval date [1] 318365 0
26/08/2025
Ethics approval number [1] 318365 0
2025/HRE00139

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

Contacts
Principal investigator
Name 143958 0
Prof Reg Nixon
Address 143958 0
Flinders University, Sturt Rd, Bedford Park South Australia 5042
Country 143958 0
Australia
Phone 143958 0
+61 8 8201 2748
Fax 143958 0
Email 143958 0
[email protected]
Contact person for public queries
Name 143959 0
Olivia Waring
Address 143959 0
Flinders University, Sturt Rd, Bedford Park South Australia 5042
Country 143959 0
Australia
Phone 143959 0
+61 08 8201 5995
Fax 143959 0
Email 143959 0
[email protected]
Contact person for scientific queries
Name 143960 0
Reg Nixon
Address 143960 0
Flinders University, Sturt Rd, Bedford Park South Australia 5042
Country 143960 0
Australia
Phone 143960 0
+61 8 8201 2748
Fax 143960 0
Email 143960 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.