A mindfulness-based, cognitive, social, digital relapse-prevention intervention for youth with depression in Australia: study protocol for a randomised controlled trial of Rebound

Abstract

Introduction
Major depressive disorder (MDD) causes significant disease burden and functional impairment during adolescence and young adulthood. While most young people recover from their first episode, around two-thirds will experience one or more relapses, which can become more severe and treatment-resistant with each episode. To address relapse in MDD, we developed a moderated online social therapy platform (titled Rebound ) that integrates: (i) peer-to-peer social networking; (ii) tailored third-wave therapeutic content targeting mindfulness, self-compassion and rumination; and (iii) three types of human support (clinicians, peer workers, career consultants), informed by self-determination theory. The aim of this trial is to determine whether, in addition to treatment as usual (TAU), Rebound , an 18-month complex digital intervention, is superior to 18 months of enhanced TAU in preventing relapse and managing depressive symptoms.

Methods and analysis
This study is a rater-masked randomised controlled trial. The treatment conditions include Rebound plus TAU or enhanced TAU alone. We aim to recruit 255 young people with at least one episode of MDD, aged 14–27 years. The study includes monthly assessment points over 18 months. The study includes a 48-month recruitment period and an 18-month treatment phase. The primary outcome is depressive relapse at 18 months, as measured by the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), Research Version (SCID-5-RV). Secondary outcomes include the severity of depressive symptoms, time to relapse, time to remission, remission status, severity of anxiety symptoms, study and employment outcomes and cost-effectiveness. We will also examine four therapeutic mechanisms (mindfulness, self-compassion skills, social support and reduced rumination) to understand the ‘how and why’ of the intervention effects.

Ethics and dissemination
Melbourne Health Human Research Ethics Committee (HREC/42967/MH-2018) provided ethics approval for this study. Findings will be made available through scientific journals and forums and to the public via social media and the Orygen website.

Trial registration number
ANZCTR, ACTRN12619001412123.

Full text

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MangelsdorfSN, etal. BMJ Open 2024;14:e088695. doi:10.1136/bmjopen-2024-088695
Open access
A mindfulness- based, cognitive, social,
digital relapse- prevention intervention
for youth with depression in Australia:
study protocol for a randomised
controlled trial of Rebound
Shaminka N Mangelsdorf,1,2 Daniela Cagliarini ,1,2 Yong Yi Lee,3,4,5
Cathrine Mihalopoulos ,3 Virginia Liu,1 Lee Valentine,1,2 Sarah Bendall,1,2
Peter Koval,6,7 Simon D'Alfonso,8 Christopher Davey,9 Penni Russon,10
Jess Phillips,11 Cesar Gonzalez- Blanch ,2,12 Brendan Pawsey,13
Richard M Ryan,14,15 Alexandra Parker,1,16 Sarah Hetrick,17 Simon Rice,1,2,18
Reeva Lederman,8 Helen Herrman,1,2 Greg Murray,19 John Gleeson,20
Mario Alvarez- Jimenez1,2
To cite: MangelsdorfSN,
CagliariniD, LeeYY, etal. A
mindfulness- based, cognitive,
social, digital relapse-
prevention intervention for
youth with depression in
Australia: study protocol for
a randomised controlled
trial of Rebound. BMJ Open
2024;14:e088695. doi:10.1136/
bmjopen-2024-088695
►Prepublication history
and additional supplemental
material for this paper are
available online. To view these
les, please visit the journal
online (https://doi.org/10.1136/
bmjopen-2024-088695).
SNM and DC are joint rst
authors.
Received 13 May 2024
Accepted 03 September 2024
For numbered afliations see
end of article.
Correspondence to
Mrs Daniela Cagliarini;
daniela. cagliarini@ orygen.
org. au
Protocol
© Author(s) (or their
employer(s)) 2024. Re- use
permitted under CC BY.
Published by BMJ.
ABSTRACT
Introduction Major depressive disorder (MDD) causes
signicant disease burden and functional impairment
during adolescence and young adulthood. While most
young people recover from their rst episode, around
two- thirds will experience one or more relapses, which
can become more severe and treatment- resistant with
each episode. To address relapse in MDD, we developed a
moderated online social therapy platform (titled Rebound)
that integrates: (i) peer- to- peer social networking;
(ii) tailored third- wave therapeutic content targeting
mindfulness, self- compassion and rumination; and (iii)
three types of human support (clinicians, peer workers,
career consultants), informed by self- determination theory.
The aim of this trial is to determine whether, in addition to
treatment as usual (TAU), Rebound, an 18- month complex
digital intervention, is superior to 18 months of enhanced
TAU in preventing relapse and managing depressive
symptoms.
Methods and analysis This study is a rater- masked
randomised controlled trial. The treatment conditions
include Rebound plus TAU or enhanced TAU alone. We
aim to recruit 255 young people with at least one episode
of MDD, aged 14–27 years. The study includes monthly
assessment points over 18 months. The study includes a
48- month recruitment period and an 18- month treatment
phase. The primary outcome is depressive relapse at
18 months, as measured by the Structured Clinical
Interview for the Diagnostic and Statistical Manual of
Mental Disorders, Fifth Edition (DSM- 5), Research Version
(SCID- 5- RV). Secondary outcomes include the severity of
depressive symptoms, time to relapse, time to remission,
remission status, severity of anxiety symptoms, study and
employment outcomes and cost- effectiveness. We will also
examine four therapeutic mechanisms (mindfulness, self-
compassion skills, social support and reduced rumination)
to understand the ‘how and why’ of the intervention
effects.
Ethics and dissemination Melbourne Health Human
Research Ethics Committee (HREC/42967/MH- 2018)
provided ethics approval for this study. Findings will be
made available through scientic journals and forums and
to the public via social media and the Orygen website.
Trial registration number ANZCTR,
ACTRN12619001412123.
INTRODUCTION
Adolescence and young adulthood are a time
of forming social connections, exploring
identity and engaging in work and study.1
Alongside already significant physical and
emotional development, the onset and recur-
rence of major depressive disorder (MDD)
can significantly affect a young person’s
STRENGTHS AND LIMITATIONS OF THIS STUDY
⇒Rebound is the rst intervention to harness scalable
digital technology to deliver a mindfulness- based
intervention to prevent depressive relapse and man-
age depressive symptoms in youth diagnosed with
major depressive disorder (MDD).
⇒Rebound was developed by a multidisciplinary
team in partnership with young people and clini-
cians, which may enhance the acceptability of the
intervention.
⇒The purpose of Rebound is to scale across and em-
bed within youth mental health services.
⇒The Rebound study is the longest known study (18
months) of a digital intervention addressing relapse
in youth diagnosed with MDD.
⇒Due to the nature of psychosocial interventions, par-
ticipants and clinicians were not masked to treat-
ment allocation.
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social functioning, physical health and quality of life.2
MDD is a common and often recurrent mental health
condition, affecting approximately 12% of young people
aged between 15 and 24 years.3 4 Globally, depression is
the leading cause of disability5 and has increased in prev-
alence since the COVID- 19 pandemic.6 Around 80%
of children and young people accessing mental health
services have a diagnosis of MDD.7 Depressive symp-
toms, alongside anxiety, represent the most common
presenting problem of those accessing Australian, entry-
level youth mental health services like headspace.8 While
most young people recover from their first episode of
MDD, around two- thirds will experience a relapse.9 The
course of MDD shows a worsening pattern, with each
episode occurring sooner, increasing in severity and
becoming more resistant to effective treatments.10 There-
fore, treatments must be timely, efficient and effective
for those experiencing their first episode or who are at
risk of subsequent episodes of depression. Unfortunately,
even in high- income countries like Australia, the mental
health system offers the opposite: delayed access to care
due to limited availability of services and long waitlists
and while in care, insufficient or mismatched treatments
as indicated by many young people not reaching clinically
significant improvement by the end of care.8 11
Digital mental health interventions may help to
address systemic challenges by providing timely, acces-
sible, evidence- based treatments.12 Digital interventions
can be offered to young people while waiting for face- to-
face care, during care, and on discharge and can extend
the in- person ‘therapy hour’ by building on skills and
concepts introduced in therapy.13 This means that digital
interventions can treat current and emerging mental
health disorders and support relapse prevention after
remission. Moreover, digital mental health interventions
are feasible and acceptable for use with young people
experiencing depression.14 Digital health interventions
have been shown to reduce the rate of hospital admis-
sions and emergency service use and be both cost- saving
and cost- effective for young people with serious mental
ill- health over 18 months compared with treatment as
usual (TAU).15 16
Despite the benefits of digital mental health interven-
tions, engagement with and completion of online therapy
content tend to be low.17 Real- time or ‘synchronous’
human support from a trained mental health professional
improves engagement rates as mental health profes-
sionals can provide supportive accountability and moti-
vational support.18 19 Furthermore, to provide an effective
intervention, human support needs to lead to ‘effec-
tive’ engagement, which includes behaviour change.20
Behaviour change may also be supported by trained
mental health professionals through the application of
behaviour change techniques. Self- determination theory
(SDT) is a theory of motivation that posits individuals are
motivated in the most sustainable and healthy ways when
they experience optimal levels of autonomy, competence
and relatedness.21 SDT has been operationalised into
evidence- based behaviour change techniques that can be
applied to the provision of human support online.22
Rebound is a complex digital mental health interven-
tion23 as it targets youth depression and prevents depres-
sive relapse through the integration of several interacting
components: (1) youth- friendly, evidence- based thera-
peutic content targeting mechanisms of mindfulness, self-
compassion and rumination; (2) three types of human
support (clinicians, peer workers and career consul-
tants) applying evidence- based SDT- informed behaviour
change techniques; and (3) a supportive online commu-
nity of peers and peer workers sharing lived and living
experience of mental ill- health, who aim to increase
social support and decrease loneliness. Rebound has been
iteratively developed with young people and a multidisci-
plinary team of clinicians, creative writers and developers
over the past decade, using the Moderated Online Social
Therapy (MOST) model.24–26 In a single- arm pilot trial
(n=42), Rebound has been found to be safe, acceptable,
and feasible and significantly improved depressive symp-
toms at a 12- week follow- up.14
The primary aims of the current study are:
1. To evaluate, via a randomised controlled trial (RCT),
the effectiveness of the Rebound platform in prevent-
ing relapse of MDD in young people with MDD (aged
14–27 years).
2. To evaluate the cost- effectiveness of the Rebound plat-
form via a concurrent within- trial economic evaluation.
3. To examine four therapeutic mechanisms (mindful-
ness skills, self- compassion, social support and reduced
rumination).
The primary hypothesis is that relative to enhanced
TAU, TAU plus Rebound will reduce the accumulated
relapse rate over 18 months among young people with
MDD. The secondary hypotheses are that relative to
enhanced TAU, TAU plus Rebound will generate improve-
ments in depressive symptoms, reduce time to relapse
and time to remission, reduce remission rates, improve
anxiety symptoms, and improve study and employment
outcomes over 18 months; be more cost- effective; and
help to prevent relapse in MDD by increasing mindful-
ness skills, self- compassion, social support and reducing
rumination.
METHOD
Study design
The study design is a prospective, parallel group, rater-
masked RCT. Approximately 255 participants with MDD
will be allocated to either enhanced TAU or TAU in
tandem with a complex moderated online social media
intervention (TAU+Rebound).
The trial includes a 48- month recruitment period
and an 18- month treatment phase, with the study being
completed within 5.5 years. The design comprises monthly
assessment points across 18 months. The protocol devel-
opment addressed all aspects of Good Clinical Practice,27
CONSORT EHEALTH criteria28 and SPIRIT guidelines.29
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Setting
Participant recruitment commenced in October 2019
at services in the North- Western Melbourne (Victoria,
Australia) catchment, specifically the Youth Mood Clinic
(YMC), a programme of Orygen Specialist Program
(OSP) and headspace centres led by Orygen (in the
Melbourne suburbs of Sunshine and Glenroy).30 31
Orygen is the world’s leading research and knowledge
translation organisation focusing on mental ill- health in
young people.
Orygen Digital, the digital mental health division of
Orygen and Centre for Youth Mental Health at University
of Melbourne, designs, delivers and evaluates evidenced-
based digital services for youth mental health. In April
2020, Orygen Digital commenced implementation of the
MOST platform across all Victorian youth mental health
services as part of the Victorian State Government’s
response to the COVID- 19 pandemic and the recommen-
dations of the Royal Commission into Victorian Mental
Health system.11 Due to the overlap between study and
implementation sites, participant recruitment from Victo-
rian sites ceased in October 2020. Instead, satellite recruit-
ment sites were established at headspace services in the
Illawarra region, New South Wales (NSW), operated by
Grand Pacific Health (Wollongong, Bega, Nowra, Goul-
burn) and two services within the South Eastern Sydney
Local Health District (Bondi Junction Community Mental
Health Centre and headspace Bondi Junction).
Patient and public involvement
The Rebound intervention has been co- designed with
young people, following strict participatory design prin-
ciples32 with continual feedback from young people
across the development, pilot and intervention period.
Consistent with best practice in developing novel inter-
ventions,33 we have obtained feedback from participants
in the Rebound pilot14 about the need for more visually
engaging therapy content. As a result, we have incorpo-
rated graphic narratives and comics to enhance engage-
ment with therapy content in Rebound. Participants in the
intervention group will be invited to regular focus groups
with the emphasis being on feedback and questions about
the intervention. More broadly, the protocol and partici-
pant information and consent forms have been reviewed
by the Orygen Youth Research Council, and the investi-
gator group carefully considered the burden of the trial
schedule of assessments on participants.
Participants
Inclusion criteria for participants are: (a) age 14 to 27
years inclusive; (b) able to read and converse in English;
(c) able to provide informed consent; (d) able and willing
to nominate an emergency contact person, such as a close
family member; (e) diagnosis of MDD (current, partial or
full remission) corresponding to the current episode of
care as measured by the SCID- 5- RV;34 and (f) ≥ 1 episode
of MDD if in partial remission at time of screening assess-
ment or ≥2 episodes of MDD (including the current
episode) if current MDD or MDD in full remission at time
of screening assessment.
Exclusion criteria are: (a) inability to converse in or
read English; (b) acute risk of self- harm requiring urgent
intervention (ie, suicidal ideation with a current plan and
intent to enact this plan) at time of screening assessment;
(c) a diagnosed permanent developmental delay or intel-
lectual disability; (d) current or past episode of mania
or hypomania; and (e) previous exposure to a MOST
platform.
Enrolment and randomisation
Participants are recruited from primary and specialist
youth mental health services. In Victoria, study research
assistants (RAs) attend weekly clinical review meetings at
YMC and headspace services to identify eligible clients. In
NSW, a study clinical liaison has been appointed at satel-
lite sites to actively facilitate recruitment at the site. The
study liaison attends clinical review meetings, engages
with treating clinicians and screens clinical files to identify
potentially eligible clients. The study liaison introduces
the trial to the client and obtains consent to share contact
details with Orygen. Young people can also self- refer via
the study recruitment page on the Orygen website.
The RA contacts potential participants, provides a
detailed explanation about the trial and offers to answer
questions. All participants are required to provide
informed, signed consent. Parental or legal guardian
consent is required for participants under 18 years of age.
Once consent is obtained, the participant is enrolled in
the trial and a screening assessment to assess eligibility
is conducted by the RA. Once eligibility is established,
the baseline assessment is completed. After completing
the baseline assessment, the participant is randomised by
the RA via a secure online Research Project Management
System (RPMS). The RPMS sends an automated email
to the study coordinator and principal investigator, noti-
fying them of the outcome of randomisation. The study
coordinator informs the participant of the allocation.
Participants are reimbursed for their time for each assess-
ment completed.
The randomisation schedule is generated by a stat-
istician independent of the study, programmed in the
RPMS and not accessible by the study team. Participants
are randomly assigned to the treatment condition via the
RPMS using randomly permutated blocks with a 1:1 allo-
cation ratio. Participants are stratified by current MDD
status (current, partial or full remission), number of
previous MDD episodes (≤ 2 or ≥ 3), age (<18 years and
≥18 years), sex at birth and by treatment centre.
Enhanced treatment as usual (TAU)
TAU consists of a range of treatment options delivered by
the treating service prior to discharge30 31 and/or generic
medical or mental health services typically available to
young people in the absence of enrolment in the study.
These can include follow- up by a general practitioner,
private psychiatrist, primary care youth mental health
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services or adult mental health services, which deliver
multidisciplinary psychiatric care (including medical
follow- up, case management and acute psychiatric care as
appropriate). Online psychoeducation is also offered to
those allocated to enhanced TAU to match the additional
support offered to the intervention group. Psychoeduca-
tion is beneficial as an adjunctive treatment for depres-
sion and is readily translated into web- format.35 The study
team developed a web application called ‘Empower Your
Mood’ (EYM) that includes psychoeducation modules on
depression symptoms, causes and course, behaviour and
mood, information on diet, exercise, sleep, social support
and getting support. In contrast to the Rebound platform,
EYM is a static website and does not include clinician
support or an online community. All modules are avail-
able for 18 months to match the Rebound intervention’s
timeframe.
Intervention
Rebound is a complex, multicomponent intervention23
based on the MOST model.14 15 24–26 The design of Rebound
considers SDT principles to best support intrinsic motiva-
tion36 (see table 1). Each component of Rebound will be
introduced in turn.
Therapeutic content
To scaffold the building of competence, the thera-
peutic content on Rebound is presented in ‘bite- size’
chunks—thematically related ‘activities’ that are organ-
ised into ‘tracks’—that are clustered within ‘journeys’.
There are five activity types: comics, reflective actions, actions,
talking points and pages. Comics are illustrated multi-
paneled narratives that bring therapeutic concepts to
life via recurring characters and story (see figure 1 for
an excerpt), reflective actions provide a clear prompt for
reflection, actions suggest a practical step (eg, behavioural
experiment), talking points prompt young people and
peer workers to post their thoughts and reactions to the
content, and pages summarise each track and provide
psychoeducation. Users have the option to save activities
to a ‘toolkit’, so they have an accessible, personalised and
labelled bank of strategies when needed.
Rebound includes five ‘journeys’, each with a different
focus: managing depression (‘Improve Your Mood’),
managing anxiety (‘Find Your Calm’), overcoming social
anxiety (‘Find Your Confidence’), managing insomnia
(‘Feeling Tired’) and enhancing social functioning
(‘Social Hacks’). There is also one journey based on work
and study- related issues. Users can access one journey at
a time and on- demand ‘Explore’ activities alongside their
journey.
Participants randomised to the TAU+Rebound condi-
tion are initially offered the Improve Your Mood journey,
which adopts a trans- therapeutical approach to depres-
sive relapse prevention using Mindfulness- Based Cogni-
tive Therapy, Acceptance and Commitment Therapy and
Cognitive Behavioural Therapy principles. The Improve
Your Mood journey contains over 50 activities, which are
available over the 18 months of the trial. The Improve
Your Mood journey targets rumination and worry,
behavioural inactivation and avoidance by introducing
the following strategies: mindfulness, behavioural acti-
vation, values, defusion, cognitive restructuring, accep-
tance, self- compassion and gratitude.
Peer-to-peer online social networking (‘the community’)
The online ‘community’ allows young people and
peer workers to develop a profile listing their interests
(‘members’ page) and to post text, images and links
(‘feed’ page). On the community feed, peer workers
post regularly about their lived and living experience of
mental health (see figure 2) and contribute ice break-
er–type posts about their interests. When contributing a
post to the feed, users also have the option to apply the
‘vent’ function to the post, which allows users to include
certain offensive words (most commonly swear words)
that would otherwise be blocked by the MOST system.
Vent posts are by default collapsed in the feed so that their
viewing is optional, and other users who wish to see such
posts are required to click expand to view them. Users
may ‘react’ (eg, ‘I get you’, ‘thinking of you’) or comment
in response to a post. The community is designed to facili-
tate social support and enhance relatedness.
The community also includes Talk it Out (TiO), a struc-
tured problem- solving function that steps a young person
through developing a question (eg, How can I manage
stress?), provides an opportunity for the young person
to crowdsource solutions and checks in with their prog-
ress. TiO was informed by the Social Problem- Solving
Framework.37
Human support
There are three types of human support (or ‘modera-
tion’) offered via Rebound: clinicians, peer workers and
career consultants. These moderators work together to
provide care for each user of Rebound using SDT- informed
Table 1 Self- determination theory (SDT)- informed platform features
SDT principle Brief denition Moderated Online Social Therapy platform feature
Autonomy Freely chosen actions, including genuine interest,
value and appreciation for the activity
Personalised approach and exibility in support and
content options
Competence A sense of growth through progressive mastery over
a task
Bite- sized therapeutic content, demonstrating
progress in content completion, toolkit of saved items
Relatedness Meaningful and supportive bi- directional social
connections
Online community and talking points
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engagement strategies (see table 2). Rebound moderators
meet fortnightly as a whole team and weekly in discipline-
specific groups to review engagement on the platform
and revise SDT- related strategies to support motivation.
Moderators can also communicate with one another via
chat messaging and activity logs on Rebound.
Clinicians. Each young person on Rebound is allocated
a qualified mental health clinician (eg, clinical psychol-
ogist, social worker) with experience working with
young people. During the initial ‘welcome call’, clini-
cians welcome young people to the platform, provide a
platform orientation, support goal setting and develop
a formulation. After this, clinicians contact the young
person weekly for 12 months (via phone/SMS/chat) to
support engagement with therapy content, suggest and
tailor therapy content, and act as a liaison between the
young person and other forms of human support. In their
final 6 months, clinicians reduce contact to monthly.
To maintain usability, relevance and uptake of content,
clinical moderators tailor journey content to each user’s
immediate needs. Tailoring is also based on the user’s
remission status. For example, for participants who are
actively depressed, activities related to behavioural acti-
vation/motivation, sleep hygiene and avoidance may be
prioritised, while those in full remission may focus on
mindfulness, values/strengths, wellness planning and
developing their toolkit. Cognitive strategies (ie, restruc-
turing, defusion) and self- compassion are addressed
regardless of remission status. Users may also choose to
switch to a different journey in consultation with their
allocated clinician.
Importantly, the clinician monitors the clinical status
of young people in their caseload and conducts twice-
daily safety checks of the platform. The clinical team
Figure 1 Excerpt of the ‘Three Minute Breathing Space’
comic.
Figure 2 An example community post (de- identied and
used with permission).
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Table 2 Self- determination theory (SDT)- informed engagement strategies22
SDT concept Strategies22 Relevance to moderation on Rebound
Autonomy Use non- judgemental language that suggests, rather than
demands.
Note sources of internal and external pressure.
Encourage the user to develop their own understanding of their
mental health.
Provide a clear rationale for suggestions.
Explore the user’s values and aspirations.
Provide choices (including the choice not to change).
Encourage experimentation with new skills, with debrieng.
Clinical formulation development.
Encouraging reection in 1:1 interactions.
Moderation team being mindful to not place pressure on user
in interactions.
Explore sources of internal/external pressure in 1:1
interactions, particularly with peer work/clinicians.
Create culture within moderation team of speaking to one
another non- judgementally and then spread culture to platform.
Apply strategies to goal setting on platform.
Link journey/platform engagement to values.
Develop shared rationale for journey/platform engagement.
Provide choices about goal setting, journey tailoring, mode and
frequency of contact.
Support engagement in reective actions.
Encourage light, fun and experimental actions.
Competence Discuss barriers and how to overcome them.
Clarify goals.
Support the user to set realistic goals.
Validate progress being made.
Support the user to develop a plan to meet their goals.
Encourage the user to self- monitor progress.
Explore dealing with unhelpful internal and external pressure.
Ensure user knows that you are guring out the barriers
together—reduces power imbalance.
Complete part of journey with user to identify and troubleshoot
barriers in real time.
Clinicians help user to identify what they expect of themselves
and encourage consideration of what they have capacity for.
Peer workers share experiences of process of change.
Clinicians and career consultants help user to set personalised
and realistic goals on a realistic timeline.
Clarify differences between long- term and short- term goals.
Clarify differences between goal- setting on MOST vs other
types of support (eg, face- to- face).
Career consultants provide feedback on resumes and cover
letters.
Clinicians provide encouragement and validation when
progress made (eg, completion of activities).
Clinicians provide feedback on reective actions and skill
development (eg, mindfulness); user identies strengths
through questionnaire, and moderators can identify and point
out strengths in action.
Setting realistic amounts of activity on platform per day (eg,
2 min, one activity) in order to meet longer term goals (eg,
complete journey).
Using non- controlling language, acknowledging the present
‘capacity’ of the user.
Reminding them of when they have overcome pressure in the
past.
Encouraging them to explore what is internal/external pressure.
Ask questions to prompt reection on why they are doing what
they're doing—align with core values.
Provide a rationale for why we are asking user to engage.
Acknowledge pressure that can be experienced.
Provide information about work rights.
Encourage boundaries.
Relatedness Respect the user’s perspective.
Encourage the user to ask questions.
Demonstrate unconditional positive regard.
Demonstrate genuine interest in the user.
Listen empathetically.
Check the user’s available supports and link them in to support
where needed.
Provide validation and empathy in all interactions.
Validate before jumping to problem- solving.
Encourage user to ask questions of moderators and in the
community, particularly using TalkitOut.
Encourage self- reection on progress.
Build trust so that user feel comfortable asking questions.
Regularly ask if user have any questions.
Unconditional positive regard in all interactions.
Genuine interest in all interactions.
Offer choices for types of support.
Check in on supports later in user’s time on platform.
Assess supports during welcome call/initial interactions with
user.
Career consultants refer user to external supports and
resources as needed.
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meet weekly for peer supervision. Clinicians complete
fidelity checklists bi- monthly and discuss their self-
identified strengths and weaknesses during supervision
to strengthen fidelity to the moderation model and
processes.
Peer workers. Peer workers are trained young people
with lived and living experience of mental ill- health. Peer
workers are integral to the provision of social support
via Rebound—a proposed mechanism of action in the
study (eg,38 Peer workers moderate the online ‘commu-
nity’ and chat with young people on the platform. Peer
workers also lead monthly online ‘hangouts’ to reinforce
connections. The peer work model is also designed to
normalise experiences, counteract stigma, and promote
platform engagement.
Career consultants. Career consultants provide special-
ised support for work and study issues via phone and chat
including support with job applications, interviews and
career assessments.
Safety protocol
The safety protocol is comprised of three levels of security
including: (1) system and privacy protection; (2) online
safety and (3) clinical safety.
The Rebound platform is hosted on an Amazon Web
Services web server. Amazon Web Services and Orygen
Digital meet standards of responsible business practice.
Identity management and networking are handled by
Orygen Digital’s Engineering Department according to
Orygen (National) Standards, which meet Australian
research requirements. In addition, MOST has a wide
range of measures to secure the application and database
against unauthorised access. These measures conform to
industry best practice as defined by the Open Web Appli-
cation Security Project (www.OWASP.org). Privacy and
online safety are managed in accordance with the Austra-
lian Communications and Media Authority.
At onboarding, the Rebound clinician carries out an
initial orientation with Rebound participants, including
details of the terms of use. Participants are required to
accept and comply with the guidelines for safe use of
Rebound. When needed, participants are offered guidance
on appropriate usage of the system. All users are asked to
nominate an emergency contact person, such as a close
family member. Rebound includes a ‘report function’ that
enables young people to report a concern about any mate-
rial posted by a user. The moderator assesses the report
and responds accordingly, which may include removing
material and, in some cases, deactivating or restricting the
poster person’s account. Participants are also able to hide
their profile and activity should they become concerned
about their privacy.
Clinical risk is managed through both manual and auto-
mated procedures. First, clinical moderators monitor the
system two times per day on weekdays and one time per
day on weekends for evidence of clinical risk or deterio-
ration. Any detected increased risk activates the Rebound
risk and safety protocol, which includes one or more of
the following: a risk assessment with the young person,
informing the research team, alerting the emergency
contact nominated by the participant and liaising with
suitable emergency services where necessary. In addition,
the system incorporates visible emergency guidelines and
contact information. Finally, Rebound includes an auto-
mated keyword detection function, which activates each
time a participant posts a contribution indicative of clin-
ical risk or that contains potentially offensive words. The
function blocks posts with notifications sent to the young
person and the moderator, who can ‘unblock’ the post
should they determine it unproblematic.
In the event of a clinically significant deterioration of
symptoms, increased risk of suicide or a hospital admis-
sion, a clinical moderator performs an assessment to
determine the risks and benefits of a temporary with-
drawal from Rebound. Based on this assessment, and in
consultation with the young person, the clinical modera-
tion team determines whether their account is temporarily
suspended, or their level of access is restricted. Following
suspensions or restrictions to a user’s account, the clini-
cian will contact the young person at monthly intervals to
ascertain whether the account is to be reactivated.
Outcome measures
Multiple methods will be employed to assess study
outcomes (see table 3). These include independent
observer ratings, self- report and usage data from the
Rebound system.
Primary outcome and measure
The primary outcome is relapse rate (accumulated over 18
months) of MDD. Relapse will be defined as a return, for
at least 2 weeks, of symptoms sufficient to meet DSM- 5
criteria for MDD (as determined by the SCID- 5- RV)34
at any time in the 18 months post randomisation. This
definition of relapse is the one most commonly used in
clinical studies.39 Measurement of relapse will be carried
out every 3 months (ie, at 3, 6, 9, 12, 15 and 18 months).
Telephone administration of the SCID is a valid method
for measuring MDD.40 Data from the Quick Inventory
of Depressive Symptomatology Self- Report41 may also be
used to supplement the SCID assessment. A number of
strategies will be embedded to promote participant reten-
tion, including a generous assessment window, flexible
availability of RAs, minimal data collection at most time-
points and honing RA interview skills to minimise time
commitment at larger assessment points.
Secondary outcomes and measures
Secondary outcomes and measures include:
1. Depressive symptoms will be measured by the QIDS self-
report instrument41 monthly for 18 months.
2. Time to relapse will be derived from the SCID- 5- RV (Mod-
ule A: Mood Episodes) at 3, 6, 9 12, 15 and 18 months.
3. Time to remission will be derived from the SCID- 5- RV
(Module A – Mood Episodes) at 3, 6, 9, 12, 15 and 18
months.
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Table 3 Schedule of outcomes and measures
Screening/
baseline 3 months 6 months 9 months 12 months 15 months 18 months
Primary outcome and measure
Relapse of MDD (SCID- 5- RV: depression module) x x x x x x x
Secondary outcomes and measures
Depressive symptoms (QIDS- SR) Monthly
Time to relapse (SCID- 5- RV: depression module) x x x x x x x
Time to remission (SCID- 5- RV: depression module) x x x x x x x
Rate of remission (SCID- 5- RV: depression module) x x x x x x x
Time in remission (SCID- 5- RV: depression module) x x x x x x x
Anxiety (GAD- 7) x x x x
Vocational status (RUQ) x x x x
Cost- effectiveness (RUQ) x x x x
Therapeutic mechanisms and measures
Mindfulness skills (FMI) x x x x
Self- compassion (SCS- SF) x x x x
Social support (SPS) x x x x
Rumination (RRS- SF) x x x x
Exploratory outcomes and measures
Stress (PSS) x x x x
Social anxiety (LSAS) x x x x
Loneliness (UCLA Loneliness Scale) x x x x
Self- efcacy (Self- Efcacy Scale) x x x x
Self- esteem (Rosenberg SES) x x x x
Social and general functioning (SOFAS) x x x x
Suicidal ideation and attempts in past 6 months (CSSRS) x x x x
Deliberate self- harm (Risk Taking and Self- Harm Inventory†) x x x x
Psychological well- being (BPNSS) x x x x
Quality of life (AQoL- 8D) x x x x
Behavioural activation (BADS- SF) x x x x
Sleep quality (PSQI) x x x x
Strengths use (SUS) x x x x
Medication adherence (RUQ)* x x x x
Continued
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4. Rate of remission will be derived from the SCID- 5- RV
(Module A – Mood Episodes) at 3, 6, 9, 12, 15 and 18
months.
5. Time in remission will be derived from the SCID- 5- RV
(Module A: Mood Episodes) at 3, 6, 9, 12, 15 and 18
months.
6. Anxiety will be measured by the Generalized Anx-
iety Disorder 7- item scale42 at baseline, 6, 12 and 18
months.
7. Vocational status will be self- reported by participants at
baseline, 6, 12 and 18 months (including the partici-
pant’s report of employment and educational activities
in between assessments).
8. Cost- effectiveness will be assessed using a self- reported
Resource Use Questionnaire (RUQ) to determine the
broader resource use of participants (eg, community
mental health services, hospitalisations, work and ed-
ucational impacts) and the Assessment of Quality of
Life - 8 Dimensions (AQoL- 8D) questionnaire, which
measures health- related quality of life and can be used
to calculate quality- adjusted life years (QALYs).43
Measures of therapeutic mechanisms
Therapeutic mechanisms include: mindfulness skills,
measured by the Freiburg Mindfulness Inventory;44
self- compassion, measured by the Self- Compassion Scale
Short Form;45 rumination, measured by the Rumina-
tive Responses Scale- Short Form;46 and social support,
measured using the Social Provisions Scale.47 Measures
are administered at baseline, 6, 12 and 18 months.
Other measured outcomes
Additional exploratory outcomes, potential covariates
and intervention- only outcomes are outlined in table 3.
Data analysis and management
Sample size
Sample size was determined by power analysis using
G*Power 3. The primary outcome is difference in accu-
mulated relapse rate over 18 months. A previous relapse
prevention study in youth MDD reported a relapse rate
at an 18- month follow- up of 62% for TAU and 36% in
the relapse prevention group (OR=2.9).48 Since Rebound
will be compared against an enhanced TAU, we assume a
smaller effect (OR=2.5), for which a total sample of 192
people is required to achieve 85% power (alpha=0.05).
A total of 255 participants will be recruited, allowing for
a 25% attrition rate. This compares favourably with the
attrition rates in the Rebound pilot (7%) and is compa-
rable at an 18- month follow- up to the Horyzons RCT
(25%).14 15
Data management
The RPMS is used to manage all outcome data. The
RPMS includes an electronic Case Report Form (eCRF).
The RAs record participant- level data on an eCRF. These
data are subsequently entered into the eCRF section of
the RPMS. Self- report data are entered directly by the
participant. The RPMS is accessed using a secure website
Screening/
baseline 3 months 6 months 9 months 12 months 15 months 18 months
Substance use (ASSIST)* x x x x
Digital phenotype (AWARE- Light) Continuous
Affective and cognitive reactivity and social support (SEMA3 application) Daily
Intervention group- only outcomes and measures
Intervention acceptability (qualitative evaluation via semistructured interview) x
Therapeutic alliance (WAI- C, WAI- T) x x x x
Intervention use (ie, frequency, duration, pattern) Continuous
*Potential covariates.
†Risk Taking and Self- Harm Inventory for Adolescents.
AQoL- 8D, Assessment of Quality of Life - 8 Dimensions; ASSIST, Alcohol, Smoking and Substance Involvement Screening Test ; BADS- SF, Behavioural Activation for Depression Scale-
short form; BPNSS, Basic Psychological Needs Satisfaction Scale; CSSRS, Columbia- Suicide Severity Rating Scale; FMI, Freiburg Mindfulness Inventory; GAD- 7, Generalized Anxiety
Disorder 7- item scale; LSAS, Liebowitz Social Anxiety Scale; MDD, major depressive disorder; PSQI, Pittsburgh Sleep Quality Index; PSS, Perceived Stress Scale; QIDS- SR, Quick Inventory
of Depressive Symptomatology- Self- Report; RRS- SF, Ruminative Responses Scale - short form; RUQ, Resource Use Questionnaire; SCID- 5- RV, Structured Clinical Interview for DSM- 5
Disorders, Research Version; SCS- SF, Self- Compassion Scale Short Form; SEMA3, Smartphone Ecological Momentary Assessment; SES, Self- Esteem Scale; SOFAS, Social and Occupational
Functioning Assessment Scale; SPS, Social Provisions Scale; SUS, Strengths Use Scale; UCLA, UCLA Loneliness Scale (Version 3); WAI- C, Working Alliance Inventory client version; WAI- T,
Working Alliance Inventory therapist version.
Table 3 Continued
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and is stored on a secure server. It is designed to maintain
the privacy and confidentiality of participant information
and to ensure the integrity of the data. Access to RPMS
is restricted to study personnel, and the level of access is
dependent on the person’s role.
Analysis of outcomes
Primary analyses will be undertaken on an intention- to-
treat basis. Group differences in accumulated relapse rate
at 18 months (primary outcome) will be tested using Fish-
er’s exact test. The Cox proportional hazards regression
model (survival analysis) will be used to model time to
relapse and rate of remission in each group, which will
also be used to derive the hazard function reflecting the
instantaneous probability of relapse/remission at any
time over the 18- month follow- up.49 Finally, group differ-
ences (Rebound plus TAU vs enhanced TAU) in change
over time in the continuous secondary outcomes across
the 18- month follow- up will be examined using random-
effects models. Random- effects models allow for estima-
tion of between- person differences (ie, group effects) in
within- person slopes (ie, change trajectories in secondary
outcomes) and are the preferred methods for analysing
clinical trial data.50
Mechanism of action analyses will be conducted
using a multilevel structural equation modelling frame-
work to assess mediation.51 Specifically, person- specific
slopes representing change over time in the proposed
mechanism- of- action variables will be examined as media-
tors of the effect of treatment group (Rebound vs control)
on risk of relapse.
Additional analyses will use multiple imputation to
assess the robustness of the findings to the choice of
method for handling missing data. Additional compari-
sons between treatment groups based on completers- only
analyses will be conducted. Analyses will be undertaken
in accordance with The International Council for Harm-
nonisation (ICH) 9 guidelines including a full analysis as
well as per protocol set. The per protocol sample will be
defined based on receiving a prespecified minimal expo-
sure to the online intervention (ie, more than 16 logins
over the 18- month intervention period).
The economic evaluation will comprise a cost-
consequences analysis comparing the incremental costs
of the Rebound platform (vs treatment as usual) to a wide
range of incremental study outcomes (eg, QALYs, relapse
rate). Inclusion of the AQoL- 8D questionnaire facilitates
the derivation of QALYs and enables a cost- utility analysis
to be undertaken. A study- specific RUQ was adapted for
this study from another RUQ frequently used in Austra-
lian mental health- related economic evaluations.52 The
RUQ encompasses: community- based health service use;
hospitalisations; accommodation services; medication
and diagnostic tests; impacts on education and employ-
ment; and other relevant services. Best practice within-
trial economic evaluation methods will be adopted53; and
the comparative cost- effectiveness of the Rebound plat-
form (vs treatment as usual) will be summarised using
the incremental cost- effectiveness ratio metric (eg, cost
per QALY). If the Rebound platform is found to be effec-
tive, then the lifetime and population cost- effectiveness
of the intervention will be evaluated using modelling
techniques.
Monitoring
Adverse events will be recorded throughout the trial and
serious adverse events will be reported to the sponsor
(Orygen). The study was assessed as low risk by the
sponsor, and a trial management group will be estab-
lished in place of a data monitoring committee. The
sponsor monitoring plan includes an initial monitoring
visit early in the recruitment phase which will determine
the ongoing monitoring schedule. Discontinuation of the
study will be considered where:
►A participant attempts suicide, and it is highly
likely that the attempt was caused by the Rebound
intervention.
►There are repeated instances of participants notifying
moderators about triggering or distressing content
posted by other users.
Decisions about study discontinuation will be deter-
mined by the trial management group in consultation
with the sponsor.
DISCUSSION
Accessible, timely and evidence- based treatments are
imperative to meet the demands of the present youth
mental health crisis.4 54 Rebound is a complex digital
intervention;23 unique in its length (18 months); engage-
ment principles (using SDT- informed strategies and a
multidisciplinary approach); and presentation of youth-
friendly, third- wave mindfulness- based content. It is the
first accessible, scalable treatment to prevent relapse
in youth MDD, addressing a major gap in public youth
mental health services. The study includes: an active
control group, an extended follow- up, cost- effectiveness
analysis and evaluation of theory- driven mechanisms of
action. This is likely to advance models of relapse in youth
depression and inform future intervention development.
Furthermore, the findings of this study serve to advance
our knowledge of digital adaptations of mindfulness- based
approaches and how to best engage young people online
and prevent depressive relapse. If the trial is successful,
there is a clear translation pathway for findings to the
rollout of MOST.13 Recruitment of trial participants was
finalised in September 2023. Follow- up assessments will
conclude in March 2025.
Dissemination
Findings will be made available through scientific jour-
nals and forums and to the public via social media and the
Orygen website. De- identified individual participant data
will be available after publication for 3 years via the Health
Data Australia catalogue (https://www.researchdata.edu.
au/health). Requests must include a methodologically
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sound proposal. Specific conditions of use may apply and
will be specified in a data sharing agreement (or similar)
that the requester must agree to before access is granted
(online supplemental file 1). Study protocol, informed
consent material and statistical analysis plan will also be
available.
Author afliations
1Orygen, Parkville, Victoria, Australia
2Centre for Youth Mental Health, The University of Melbourne, Parkville, Victoria,
Australia
3Monash University Health Economics Group, School of Public Health and Preventive
Medicine, Monash University, Melbourne, Victoria, Australia
4Queensland Centre for Mental Health Research, Wacol, Queensland, Australia
5School of Public Health, The University of Queensland, Herston, Queensland,
Australia
6Melbourne School of Psychological Sciences, The University of Melbourne,
Parkville, Victoria, Australia
7Research Group of Quantitative Psychology and Individual Differences, KU Leuven,
Leuven, Belgium
8School of Computing and Information Systems, The University of Melbourne,
Parkville, Victoria, Australia
9Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia
10School of Languages, Literatures, Cultures and Linguistics, Monash University,
Melbourne, Victoria, Australia
11School of Psychological Sciences, Monash University, Melbourne, Victoria,
Australia
12University Hospital Marques de Valdecilla- IDIVAL, Santander, Spain
13Mercy Health, Melbourne, Victoria, Australia
14Institute for Positive Psychology and Education, Australian Catholic University,
North Sydney, New South Wales, Australia
15College of Education, Ewha Womans University, Seoul, South Korea
16Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
17Department of Psychological Medicine, The University of Auckland, Auckland, New
Zealand
18Movember Men’s Health Institute, Melbourne, Victoria, Australia
19Centre for Mental Health and Brain Sciences, Swinburne University of Technology,
Hawthorn, Victoria, Australia
20Healthy Brain and Mind Research Centre, School of Behavioural and Health
Sciences, Australian Catholic University, Fitzroy, Victoria, Australia
X Simon D'Alfonso @sjdalf
Acknowledgements The authors wish to thank the Orygen Youth Advisory Council
for their input into the development of Rebound. The authors thank the moderation
team (Hailey, Winn, McKenzie, Harmony, Benji, James, Emily, Annette, Connor,
Evan and Ingrid) and research assistants (Jordan, Rory, Sasha, Lauren, Sheryl and
Pemma) for their valuable contributions to the study.
Contributors MA- J is the guarantor. MA- J is the principal investigator, initiated
and designed the trial, and has oversight and responsibility for the whole trial. JG
jointly oversees the conduct of the trial, and brings expertise in evaluating novel
digital youth mental health interventions. SNM and DC contributed equally—both
drafted the manuscript and led the teams responsible for intervention delivery
and recruitment and data collection, respectively. All authors contributed to
the design of the trial and critically revised the protocol manuscript. Authors
brought specic expertise in MDD and other serious mental health conditions in
youth (CD, SR, HH, CG- B, SH, SB), self- determination theory (RMR), behavioural
activation (AP), information systems research and development (RL), and digital
psychological interventions for mood disorders and strengths- based approaches
to mental disorders (GM). In addition, SDA led the passive sensing component
of the trial, CM and YYL led the economic evaluation of Rebound, PR and JP
contributed to content development, BP is the site investigator for Orygen
headspaces, SR is the site investigator for the Youth Mood Clinic, LV led the
qualitative analysis, VL led the primary statistical analysis and PK led the EMA
component of the trial.
Funding The Rebound trial was supported by a grant from the National Health and
Medical Research Council (NHMRC ID# 2018/GNT1144563) from the Australian
Government. MA- J was supported by an Investigator Grant (APP1177235) from
the National Health and Medical Research Council and a Dame Kate Campbell
Fellowship from The University of Melbourne.
Competing interests None declared.
Patient and public involvement Patients and/or the public were involved in the
design, conduct, reporting or dissemination plans of this research. Refer to the
Methods section for further details.
Patient consent for publication Not applicable.
Provenance and peer review Not commissioned; internally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has
not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been
peer- reviewed. Any opinions or recommendations discussed are solely those
of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and
responsibility arising from any reliance placed on the content. Where the content
includes any translated material, BMJ does not warrant the accuracy and reliability
of the translations (including but not limited to local regulations, clinical guidelines,
terminology, drug names and drug dosages), and is not responsible for any error
and/or omissions arising from translation and adaptation or otherwise.
Open access This is an open access article distributed in accordance with the
Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits
others to copy, redistribute, remix, transform and build upon this work for any
purpose, provided the original work is properly cited, a link to the licence is given,
and indication of whether changes were made. See:https://creativecommons.org/
licenses/by/4.0/.
ORCID iDs
DanielaCagliarini http://orcid.org/0009-0009-1461-0567
CathrineMihalopoulos http://orcid.org/0000-0002-7127-9462
CesarGonzalez- Blanch http://orcid.org/0000-0002-3181-4731
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