Investigating the benefits of the ‘One Step Back’ program for youth mental health
| ISRCTN | ISRCTN60518633 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN60518633 |
| Sponsor | National Institute for Health Research |
| Funder | National Institute for Health and Care Research |
- Submission date
- 24/08/2026
- Registration date
- 10/09/2026
- Last edited
- 01/09/2026
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Mental and Behavioural Disorders
Plain English summary of protocol
Background and study aims
Depression and anxiety are two of the most common mental health problems. People often start having symptoms when they are young. There are some psychological treatments, but one in three people do not benefit. For people who do benefit, one in three sees their symptoms return over time. This means that many people end up struggling with mental health for long periods. This puts more pressure on our mental health services.
One solution is to intervene early, during adolescence, to prevent depression and anxiety in the first place. We created a program called ‘One Step Back’ (or OSB). OSB teaches young people an essential coping skill called ‘decentering’. Decentering describes different ways of taking a mental step back to separate yourself from your thoughts and feelings; for instance, saying to yourself, “I am having a negative thought that I am useless” instead of “I am useless.” Our initial study showed that OSB reduced early symptoms of depression and increased well-being, leaving adolescents at lower risk of developing problems.
Our aim is to test OSB in a bigger study with a larger group of young people from different backgrounds who are at risk of depression. We plan to test OSB in a bigger study using a randomized controlled trial (RCT). An RCT is the best way we have to test interventions, and we are calling our trial the DECADES (Decentering in Adolescents) II Study .
Who can participate?
Adolescents aged 16-19 years from different backgrounds with levels of early depression symptoms that mean they are at risk of experiencing high levels of depression in the future
What does the study involve?
Half of the participants will be randomly selected to receive the OSB program, which involves decentering exercises using social media and online apps. The other half will complete a different ‘control’ intervention, involving physical exercises and ‘brain training’. Participants will complete exercises every day for 5 weeks. The project will take 3 years.
We involved adolescents with mental health problems in the creation of the OSB intervention and in this study proposal. They shared their ideas and opinions at each stage. We will similarly involve adolescents in all aspects of the research itself.
We will share our findings with other researchers, schools, and the public. We will present at scientific conferences, in academic papers, in schools and community support groups, and on social media.
What are the possible benefits and risks of participating?
We will learn if OSB improves adolescent mental health. OSB is easy to access, low-cost, and uses methods that young people already access. If OSB works, then we can move forward with making it available to all adolescents. This study poses minimal risk to our participants' well-being. However, reflecting on difficult thoughts, memories, and feelings during the day can sometimes cause mild distress. This experience may be particularly relevant for those with elevated symptoms of depression. The goal of the intervention is to learn a new, helpful way to reflect on these experiences. With practice, distress may ease; if not, participants are reminded that involvement is entirely voluntary, and they can withdraw at any time.
Where is the study run from?
National Institute for Health Research (NIHR) (UK)
When is the study starting and how long is it expected to run for?
September 2026 to January 2029
Who is funding the study?
National Institute for Health Research (NIHR) (UK)
Who is the main contact?
1. Marc P. Bennett, mbennett.psych@gmail.com
2. Prof. Tim. Dalgleish, tim.dalgleish@mrc-cbu.cam.ac.uk
Contact information
Principal investigator, Public, Scientific
15 Chaucer Road
Cambridge
CB2 7EF
United Kingdom
 ORCID ID |
0000-0001-7217-4059 |
|---|---|
| Phone | +44 (0)1223 766166 |
| mbennett.psych@gmail.com; marc.bennett@mrc-cbu.cam.ac.uk |
Principal investigator, Scientific, Public
15 Chaucer Road
Cambridge
CB2 7EF
United Kingdom
| ORCID ID |
0000-0002-7304-2231 |
|---|---|
| Phone | +44 (0)1223 766166 |
| tim.dalgleish@mrc-cbu.cam.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Active |
| Assignment | Parallel |
| Purpose | Prevention |
| Participant information sheet | 50140_PIS_V2.pdf |
| Scientific title | Investigation of the efficacy of the ‘One Step Back’ program: a randomized controlled trial of a digitally embedded intervention to enhance psychological decentering and reduce depression severity in at-risk adolescents |
| Study acronym | DECADES II |
| Study objectives | Determine the efficacy of the ‘One Step Back Program’ (OSB; a digitally embedded psychological decentering training intervention) in reducing depression symptoms in a targeted schools sample of at-risk adolescents. Other aims are to identify mechanisms of change that drive clinical outcomes and to explore the health-economic benefits of OSB. |
| Ethics approval(s) |
Approved 08/05/2026, Cambridge Psychology Research Ethics Committee (17 Mill Lane, Cambridge, CB2 1RX, United Kingdom; +44 (0)1223 763467; SBSEthics@admin.cam.ac.uk), ref: PRE.2026.026 |
| Health condition(s) or problem(s) studied | Early-stage onset of depression in adolescents |
| Intervention | Participants will be randomized in a 1:1 ratio to either the OSB or the active comparison arm. The trial statistician will manage allocation using a minimization procedure, stratified by age and sex. Psychological decentering training: The OSB program is a 5-week, app-based psychological intervention built on audio recordings available through online streaming/podcast providers (YouTube, Spotify, iTunes, Overcast). Participants receive an accompanying digital workbook that guides them through the intervention. Each week begins with grounding exercises to promote the naming and monitoring of mental experiences. The program then proceeds with one of four types of psychological decentering exercises. A new exercise is introduced each week and rehearsed daily for 10-15 minutes. These include: (week 1) spatial distancing, where individuals are taught to reimagine negative memories from a physically distant perspective; (week 2) verbal distancing, where individuals are taught to rephrase negative self-relevant statements to challenge their ‘believability’ and influence; (week 3) temporal distancing, where individuals are taught to reconsider specific worries from a temporally distant future; and (week 4) objective distancing, where individuals are taught to adopt a third-person perspective toward negative memories. Week 5 involves revisiting each exercise. Active control program: We developed a 5-week active ‘Cognitive Enrichment’ control program that matches the OSB program in duration and cognitive engagement while remaining psychotherapeutically neutral. Instead of viewing YouTube content on psychological decentering, participants will watch factual educational videos on YouTube, accessed via the same in-house tracking website. Each week (Monday through Friday), the Cognitive Enrichment curriculum is built around one of four neutral forms of educational content; example topics include ‘physical geography’, ‘world politics’, ‘technology and science’, and ‘animal kingdom and biology’. To match the OSB week 5 revision block, the CTL group will view ‘recap clips’ of previously seen content each day. As with the OSB arm, participants will provide brief feedback, including engagement and interest ratings, to ensure the control remains a plausible comparison condition. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 01/01/2029 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 16 Years |
| Upper age limit | 19 Years |
| Sex | All |
| Target sample size at registration | 5000 |
| Total final enrolment | 532 |
| Key inclusion criteria | Participants (aged 16-19 years) with elevated depression symptoms will be recruited based on scores from the Patient Health Questionnaire (PHQ) with inclusion defined as a score of 10 or higher Participants from a previous study conducted by our group who completed these assessments will be invited to take part if they: 1. Consented to be contacted again 2. Meet a predefined threshold (e.g., two standard deviations above the norm for that sample) |
| Key exclusion criteria | Participants will be ineligible if they: 1. Currently participate in regular yoga or a weekly yoga class or workshop 2. Previously (within the past 6 months)) or currently attend talk therapy and/or engage in formal meditation practice or a meditation class or workshop 3. Currently receive Child and Adolescent Mental Health Services (CAMHS) and/or private mental health care from psychiatrists and/or other allied mental health professionals 4. Are living with chronic physical illness (e.g., epilepsy, chronic pain, cancer) 5. Lack fluency in English 6. Have no access to a touchscreen smartphone compatible with the trial materials 7. Have a formal diagnosis of a neurodevelopmental condition such as autism spectrum disorder or attention deficit/hyperactivity disorder from a professional psychologist and/or psychiatrist |
| Date of first enrolment | 01/09/2026 |
| Date of final enrolment | 01/09/2028 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centres
Cambridge
CB2 7EF
England
Cambridge
CB2 3EB
England
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | Anonymised individual participant data will be made available via an open-access OSF link. The dataset will be uploaded after of the primary analyses, described in the study protocol. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Other files | 24/08/2026 | No | No | ||
| Other files | version 1.1 | 24/08/2026 | No | No | |
| Participant information sheet | version 2 | 24/08/2026 | No | Yes | |
| Protocol file | version 1.2 | 24/08/2026 | No | No |
Additional files
- 50140_PROTOCOL_V1.2.pdf
- Protocol file
- 50140_PIS_V2.pdf
- Participant information sheet
- 50140 Safety and Distress Management Protocols..pdf
- Other files
- 50140 - Consent Form (v1.1) (1).pdf
- Other files
Editorial Notes
01/09/2026: Trial's existence confirmed by Cambridge Psychology Research Ethics Committee.
