Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626000938303
Ethics application status
Help: Ethics application status
Approved
Date submitted
Help: Date submitted
29/06/2026
Date registered
Help: Date registered
29/07/2026
Date last updated
Help: Date last updated
29/07/2026
Date data sharing statement initially provided
Help: Data sharing statement date
29/07/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
Supporting Mental Health in Regional and Rural Communities: Developing and Testing SOLAR-R apps
Scientific title
A randomised controlled trial of an AI-enhanced, skills-based psychosocial app for posttraumatic stress symptoms in regional and rural Australia
Additional trial identifiers [1] 317733 0
Nil
Universal Trial Number (UTN)
Trial acronym
Related trial records

Health condition
Health condition(s) studied:
Posttraumatic stress symptoms 342620 0
Depression symptoms 342621 0
Anxiety symptoms 342622 0
Quality of life 342623 0
Condition category
Condition code
Mental Health 338771 338771 0 0
Other mental health disorders
Mental Health 338772 338772 0 0
Depression
Mental Health 338773 338773 0 0
Anxiety

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
SOLAR-R+ is a digital adaptation of the Skills fOr Life Adjustment and Resilience (SOLAR) program, tailored for adults living in regional, rural, and remote Australian communities. The program is a brief, trauma-focused, skills-based, psychosocial intervention. Participants gain access to the app by scanning a QR code provided on study recruitment materials, which directs them to download the application to a compatible iOS or Android smartphone.

The program comprises eight modules which are completed during the five-week intervention period. Content includes psychoeducation, skills training, values-based goal setting, emotion regulation strategies, strengthening social connections, managing unhelpful thinking patterns, and planning for continued recovery. Participants are encouraged to apply these skills in their daily lives between modules. The content is delivered through interactive activities, self-reflection exercises, text-based content, audio content, animations, progress-tracking features, and automated notifications. Program content is based on the established SOLAR intervention, while the app design and user experience have been specifically developed and tailored for adults living in regional, rural, and remote Australian communities. Adherence is monitored through module completion rates.

In addition to the standard SOLAR module content, SOLAR-R+ incorporates a generative artificial intelligence (AI) assistant embedded within the app. The AI assistant interacts with participants through a text-based chat interface. Participants can access the AI assistant through a dedicated chat function available from the app home screen to ask general questions about SOLAR content and activities. The AI assistant is also integrated within every module, where it offers support with module activities. The AI assistant is designed to enhance engagement with the program by providing tailored responses based on participant inputs, supporting goal setting and problem solving, facilitating skills practice, and assisting users to navigate app content and activities. Generated responses are grounded in SOLAR program content through retrieval-augmented generation methods.

The AI assistant does not provide clinical care and is intended to support participant engagement with, and application of, SOLAR program content.
Intervention code [1] 334569 0
Lifestyle
Intervention code [2] 334570 0
Behaviour
Intervention code [3] 334571 0
Treatment: Other
Description of the comparator or control
Participants randomised to the control condition will receive access to SOLAR-R, a non-AI-enhanced version of the intervention app. SOLAR-R contains the same eight modules, educational content, interactive activities, videos, animations, and automated notifications as SOLAR-R+ and is completed over a five-week period. The app is visually and functionally equivalent to the intervention version, with the only substantive difference being the absence of the embedded generative AI assistant.

Participants allocated to the control group will not be provided access to the AI assistant following study completion. Access to the study apps will cease for all participants at the end of the trial. Decisions regarding any future access to the apps will be considered following publication of the trial results.
Control group
Active

Outcomes
Primary outcome [1] 345967 0
Symptoms of posttraumatic stress
Timepoint [1] 345967 0
Baseline (0 weeks), end-of-treatment (7 weeks), and follow up (19 weeks).
Secondary outcome [1] 463967 0
Symptoms of depression
Timepoint [1] 463967 0
Baseline (0 weeks), end-of-treatment (7 weeks), and follow up (19 weeks).
Secondary outcome [2] 463968 0
Symptoms of anxiety
Timepoint [2] 463968 0
Baseline (0 weeks), end-of-treatment (7 weeks), and follow up (19 weeks).
Secondary outcome [3] 463969 0
Quality of life
Timepoint [3] 463969 0
Baseline (0 weeks), end-of-treatment (7 weeks), and follow up (19 weeks).
Secondary outcome [4] 463971 0
Subjective app engagement
Timepoint [4] 463971 0
End-of-treatment (7 weeks) and follow up (19 weeks).
Secondary outcome [5] 463972 0
Health services usage
Timepoint [5] 463972 0
Baseline (0 weeks) and follow up (19 weeks).
Secondary outcome [6] 463973 0
Perceived usefulness - User experience of AI-assistant (SOLAR-R+ intervention arm only)
Timepoint [6] 463973 0
End-of-treatment (7 weeks)
Secondary outcome [7] 465343 0
Social presence - User experience of AI-assistant (SOLAR-R+ intervention arm only)
Timepoint [7] 465343 0
End-of-treatment (7 weeks)
Secondary outcome [8] 465346 0
Perceived ease of use - User experience of AI-assistant (SOLAR-R+ intervention arm only)
Timepoint [8] 465346 0
End-of-treatment (7 weeks)
Secondary outcome [9] 465347 0
User experience and control - User experience of AI-assistant (SOLAR-R+ intervention arm only)
Timepoint [9] 465347 0
End-of-treatment (7 weeks)
Secondary outcome [10] 465348 0
Frequency of app use - Objective app engagement
Timepoint [10] 465348 0
Continuously throughout trial period: From baseline (0 weeks) through to follow up (19 weeks)
Secondary outcome [11] 465349 0
Number of modules completed - Objective app engagement
Timepoint [11] 465349 0
Continuously throughout trial period: From baseline (0 weeks) through to follow up (19 weeks)
Secondary outcome [12] 465350 0
Time spent engaging with intervention component - Objective app engagement
Timepoint [12] 465350 0
Continuously throughout trial period: From baseline (0 weeks) through to follow up (19 weeks)

Eligibility
Key inclusion criteria
1) Aged 18 years or older
2) Lives or works in a regional, rural, or remote Australian community, or has strong family, community, or personal ties to one
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
Yes
Key exclusion criteria
No exclusion criteria other than failure to meet the inclusion criteria

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)
Participants complete eligibility screening and the baseline survey within the app. Following completion, allocation is implemented automatically within the study app and concealed from participants, investigators, and data analysts throughout the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computer-generated randomisation sequence will be prepared by an independent statistician.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Sample size was determined using a Monte Carlo simulation–based power analysis under an ANCOVA framework. Assuming a small treatment effect (Cohen’s d = 0.20), a baseline–post correlation of 0.65, and 20% attrition at end-of-treatment (primary endpoint), approximately 550–600 participants are required to achieve 80% power at a two-sided alpha of 0.05. To account for uncertainty in assumptions, the target recruitment has been set at 650 participants.

An adaptive sample size re-estimation will be conducted when approximately 50% of participants have reached the primary endpoint. This blinded interim analysis will estimate nuisance parameters, including outcome variance, attrition rates, and the baseline–post correlation. No interim testing of treatment efficacy will be conducted. Based on these estimates, the final sample size may be adjusted up to a pre-specified maximum of 1000 participants.

All demographic data and baseline participant characteristics will be summarised using descriptive statistics (i.e., n, %, chi-square test of independence for all categorical variables; mean or median, standard deviation and t-test for independence for all continuous variables) for the ITT and per protocol, by treatment arm and overall.

The primary outcome will be the between-group difference in symptoms of posttraumatic stress disorder (PCL-5) at end-of-treatment. A linear multilevel regression model will be used with fixed effects for treatment allocation (SOLAR-R vs SOLAR-R+) and time, as well as a treatment arm allocation*time interaction. Baseline symptoms of posttraumatic stress symptoms and sex assigned at birth will be included as covariates. A random intercept will be included in the model to account for variance at the individual participant level. The analysis will be conducted on the ITT population. Superiority of SOLAR-R+ will be declared if the two-sided 95% confidence interval for the adjusted mean difference excludes 0 in favour of SOLAR-R+.

Secondary outcomes will also be evaluated in a similar fashion using linear multilevel regression models or generalised linear mixed models depending on the distribution of the outcome variables. Exploratory subgroup analyses may be conducted to examine the differential effects of the intervention among participants presenting with elevated symptoms of PTSD, depression, or anxiety at baseline.
Appropriate transformations may be applied to outcome variables before fitting the model if considered skewed.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
15/08/2026
Actual
Date of last participant enrolment
Anticipated
31/08/2027
Actual
Date of last data collection
Anticipated
31/12/2027
Actual
Sample size
Target
650
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 322275 0
Commercial sector/Industry
Name [1] 322275 0
The Latrobe Health Services Foundation
Country [1] 322275 0
Australia
Primary sponsor type
University
Name
Phoenix Australia – Centre for Posttraumatic Mental Health
Address
Country
Australia
Secondary sponsor category [1] 325189 0
None
Name [1] 325189 0
Address [1] 325189 0
Country [1] 325189 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 320791 0
University of Melbourne Central Human Research Ethics Committee
Ethics committee address [1] 320791 0
Ethics committee country [1] 320791 0
Australia
Date submitted for ethics approval [1] 320791 0
23/01/2026
Approval date [1] 320791 0
23/04/2026
Ethics approval number [1] 320791 0
2026-34301-79663-4

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

Contacts
Principal investigator
Name 151642 0
Prof Meaghan O'Donnell
Address 151642 0
Phoenix Australia - Centre for Posttraumatic Mental Health, Department of Psychiatry, University of Melbourne, 3/161 Barry St, Carlton VIC 3053
Country 151642 0
Australia
Phone 151642 0
+61 3 9035 5599
Fax 151642 0
Email 151642 0
[email protected]
Contact person for public queries
Name 151643 0
Abdullah Arjmand
Address 151643 0
Phoenix Australia - Centre for Posttraumatic Mental Health, Department of Psychiatry, University of Melbourne, 3/161 Barry St, Carlton VIC 3053
Country 151643 0
Australia
Phone 151643 0
+61 3 9035 5599
Fax 151643 0
Email 151643 0
[email protected]
Contact person for scientific queries
Name 151644 0
Meaghan O'Donnell
Address 151644 0
Phoenix Australia - Centre for Posttraumatic Mental Health, Department of Psychiatry, University of Melbourne, 3/161 Barry St, Carlton VIC 3053
Country 151644 0
Australia
Phone 151644 0
+61 3 9035 5599
Fax 151644 0
Email 151644 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No
No IPD sharing reason/comment: No open IPD sharing is planned, however deidentified data that support the published findings may be made available upon direct request to the study team



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.