An internet skills-based therapy to support people with bulimia or binge eating
| ISRCTN | ISRCTN10941295 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN10941295 |
- Submission date
- 09/06/2025
- Registration date
- 25/06/2025
- Last edited
- 20/06/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Mental and Behavioural Disorders
Plain English summary of protocol
Background and study aims
Bulimia nervosa (BN) and binge eating disorder (BED) are serious eating disorders that can have a major impact on both physical and emotional well-being. People with these conditions often experience episodes of eating large amounts of food in a short period, feeling unable to stop. BN also includes behaviours such as vomiting or excessive exercise in an attempt to prevent weight gain. These disorders are often linked to distress, low self-esteem, body dissatisfaction, and difficulty managing emotions. Although effective psychological treatments exist, many people, particularly those living in non-Western countries, do not receive support due to limited resources, stigma, or lack of access to care. This study aims to explore whether a skills-based psychological programme delivered entirely via the internet can help people experiencing symptoms of BN or BED. The programme is based on Dialectical Behaviour Therapy (DBT), a structured psychological approach that teaches people how to manage intense emotions, improve self-awareness, and respond to stress more effectively. The version of DBT used in this research has been adapted for online use, allowing participants to complete the course from home using a smartphone, tablet, or computer.
Who can participate?
Adult patients aged 18 to 60 who live in Iran and experience symptoms of BN or BED.
What does the study involve?
The internet-based DBT programme runs for 12 weeks. It includes weekly educational and skills-focused modules presented through video content, self-help worksheets, and regular therapist contact via secure online messaging like Email. Participants will learn and practise skills related to emotion regulation, mindfulness, distress tolerance, and building healthier relationships. Each week builds on the last, and participants are encouraged to practise the skills in their daily lives. Therapists offer weekly feedback and guidance to support progress and encourage engagement. Participants will complete online questionnaires before starting the programme, at the end of the 12-week course, and again three months later. These questionnaires will measure changes in eating disorder symptoms, binge eating, emotional regulation, anxiety, depression, self-esteem, life satisfaction, body image, and overall quality of life. Participants will also be asked to report how satisfied they were with the programme, how acceptable they found the format, and whether they experienced any difficulties or negative effects. Adherence will be monitored through engagement with skill practice, worksheet completion, and therapist communication.
What are the possible benefits and risks of participating?
By taking part in this study, individuals will not only receive structured psychological support but also contribute to important research that may help improve treatment options for others experiencing eating disorders in the future. Taking part in this study may help individuals develop a better understanding of their eating patterns, improve their emotional coping strategies, and build a more positive relationship with themselves. It may also provide early support for people who have not yet accessed treatment. While the programme is not a replacement for in-person therapy in more complex cases, it offers an accessible and structured resource that can be used flexibly. Some individuals may find that discussing difficult topics or completing exercises triggers emotional discomfort. Participants are encouraged to take breaks as needed and can contact the research team if they feel overwhelmed. Participation is entirely voluntary, and individuals can stop at any time.
Where is the study run from?
The study is being carried out by researchers at University College London (UCL) in partnership with Iran University of Medical Sciences. It is conducted entirely online, allowing people from different regions of Iran to participate without needing to travel.
When is the study starting and how long is it expected to run for?
December 2022 to October 2026
Who is funding the study?
The study is part of a PhD research project and does not currently have external funding
Who is the main contact?
The lead researcher is Bahareh Dastan, a doctoral student at UCL, bahareh.dastan.21@ucl.ac.uk
Contact information
Public, Scientific, Principal Investigator
University College London
Psychology and Human Development
Institute of Education
25 Bedford Way
London
WC1E6BT
United Kingdom
 ORCID ID |
0000-0002-7772-3165 |
|---|---|
| Phone | +44 (0)7467 058274 |
| bahareh.dastan.21@ucl.ac.uk |
Public, Scientific, Principal Investigator
University College London, Gower Street
London
WC1E 6BT
United Kingdom
| ORCID ID |
0000-0002-3771-9735 |
|---|---|
| Phone | +44 (0) 20 7679 2000 |
| a.harrison@ucl.ac.uk |
Public, Scientific, Principal Investigator
Iran University of Medical Sciences
Hemmat Expressway
End of the Faculty of Medicine building
Tehran
1449614535
Iran
| ORCID ID |
0000-0002-5011-2823 |
|---|---|
| Phone | +989122387577 |
| Babakhabibius@yahoo.com |
Study information
| Study design | Single-center two-arm parallel-group pilot randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Internet/virtual |
| Study type | Quality of life, Treatment, Efficacy |
| Scientific title | Internet-based dialectical behaviour therapy skills training for bulimia nervosa and binge eating disorder: protocol and preliminary results of a randomised controlled trial comparing web-based sessions and waitlist control |
| Study acronym | iDBT |
| Study objectives | Participants with bulimia nervosa (BN) and binge eating disorder (BED) who receive the internet-based dialectical behaviour therapy skills training (iDBT-ST) will demonstrate significantly greater reductions in eating disorder symptoms (measured by EDE-Q and EDDS) compared to participants in the waitlist control group at post-intervention assessments. |
| Ethics approval(s) |
1. Approved 10/01/2023, IOE PHD Doctoral Research Ethics Committee Psychology and Human Development UCL Institute of Education (20 Bedford Way, London, WC1H 0AA, United Kingdom; +44 (0) 20 7679 2000; ioe.cde@ucl.ac.uk), ref: IOEPHD100123 2. Approved 26/12/2022, Research Ethic Committees of Iran University of Medical Science (Iran University of Medical Sciences Hemmat Expressway, Tehran End of the Faculty of Medicine building After the second glass door, Tehran, 1449614535, Iran; +98 21 8670 4757; hprc@iums.ac.ir), ref: IR.IUMS.REC.1401.736 |
| Health condition(s) or problem(s) studied | Eating disorders: bulimia nervosa (BN) and binge eating disorder (BED) |
| Intervention | This study focuses on two eating disorders: bulimia nervosa (BN) and binge eating disorder (BED). Both conditions involve recurrent episodes of binge eating, with BN also characterised by compensatory behaviours such as purging. The study targets adults experiencing these disorders, along with associated difficulties such as body image dissatisfaction, emotional dysregulation, and low self-esteem, which significantly impact quality of life. The intervention is delivered as an internet-based psychological treatment, improving accessibility for individuals with internet access, particularly in contexts where face-to-face treatment is limited or unavailable. This study is a single-center, two-arm, parallel-group pilot randomised controlled trial comparing a 12-week internet-based dialectical behaviour therapy skills training (iDBT-ST) intervention to a waitlist control group (Phase 2), followed by a qualitative interview study using a within-participants design to explore participant experiences of the intervention (Phase 3). This study includes two arms: Intervention Group (iDBT-ST) : Participants in this group will receive a 12-week iDBT-ST programme designed specifically for individuals with BN and BED. The programme includes weekly web-based modules covering core DBT skills (mindfulness, emotion regulation, and distress tolerance), delivered via a secure online platform. Each session will consist of instructional videos, interactive exercises, and guided homework tasks. Participants will receive weekly written feedback from a trained therapist through Email or any communication system. Sessions will be unlocked sequentially and will last approximately 20–60 minutes each. Follow-up assessments will take place at post-intervention and 3 months after treatment completion. Control Group ( Waitlist Control) : Participants in the waitlist control group will not receive any active treatment during the initial 12-week study period. They will continue with treatment as usual (if any) and will complete the same outcome assessments as the intervention group. After the 12 weeks and post-assessment, participants will be offered access to one of the intervention formats, depending on availability and preference. Participants will be randomly assigned in a 1:1 ratio to either the intervention or waitlist control group using a computer-generated sequence via Randomizer.org or SPSS (v26). An independent researcher not involved in recruitment will generate the sequence, with allocation concealed until after baseline assessment. |
| Intervention type | Behavioural |
| Primary outcome measure | The following primary outcome measures are assessed at at baseline, week 12 (post-treatment), and 3-month follow-up: 1. Eating disorder symptoms are measured using the Eating Disorder Examination Questionnaire (EDE-Q) 2. Binge eating severity is measured using the Binge Eating Scale (BES) 3. Emotion regulation difficulties are measured using the Difficulties in Emotion Regulation Scale (DERS) |
| Secondary outcome measures | 1. Self-esteem is measured using the Rosenberg Self-Esteem Scale (RSES) at baseline, week 12, and 3-month follow-up 2. Anxiety symptoms are measured using the Generalised Anxiety Disorder-7 (GAD-7) at baseline, week 12, and 3-month follow-up 3. Depressive symptoms are measured using the Patient Health Questionnaire-9 (PHQ-9) at baseline, week 12, and 3-month follow-up 4. Overall quality of life is measured using the World Health Organization Quality of Life questionnaire (WHOQOL-BREF) at baseline, week 12, and 3-month follow-up 5. Life satisfaction is measured using the Satisfaction With Life Scale (SWLS) at baseline, week 12, and 3-month follow-up 6. Treatment satisfaction is measured using the Client Satisfaction Questionnaire (CSQ-I) at week 12 7. Treatment adherence is measured through participant engagement in weekly skill practice, completion of DBT worksheets, and participation across the 12-week intervention period. Adherence will be monitored through module completion, login frequency (where applicable), frequency of communication with the therapist via secure social messaging platforms, and consistency in practising assigned DBT skills. 8. Perceived acceptability and appropriateness of the intervention are measured using the Attitudes Toward Psychological Online Interventions (APOI) at baseline, and week 12 |
| Overall study start date | 01/12/2022 |
| Completion date | 01/10/2026 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 60 Years |
| Sex | Both |
| Target number of participants | 68 |
| Key inclusion criteria | 1. Individuals who seek treatment for bulimia nervosa (BN) and binge eating disorder (BED) according to DSM-5 (American Psychiatric Association, 2013) 2. Individuals aged 18–60 years who have a BMI of 18.5 or more 3. Literate in reading and writing 4. Need to have access to a computer, tablet, or cell phone (with a camera and microphone) and high-speed internet |
| Key exclusion criteria | 1. Individuals with a BMI less than 18.5 2. Pregnant women and individuals with substance dependence 3. Patients with major psychiatric disorders or acutely suicidal tendencies, patients who are receiving any kind of psychotherapy specifically for BED and BN 4. Existence of a current major medical illness that would interfere with treatment (e.g., cancer or diabetes or hypothyroidism 5. Patients on antidepressant medication or sleep medication who have not been on a stable dose for at least 4 months 6. Individuals follow any diet |
| Date of first enrolment | 03/11/2023 |
| Date of final enrolment | 01/10/2025 |
Locations
Countries of recruitment
- Iran
Study participating centre
Tehran
1449614535
Iran
Sponsor information
University/education
20 Bedford Way
London
WC1H 0AL
England
United Kingdom
| Phone | +44 (0) 20 7679 2000 |
|---|---|
| studentfunding@ucl.ac.uk | |
| Website | https://www.ucl.ac.uk/ |
"ROR" |
https://ror.org/02jx3x895 |
Funders
Funder type
University/education
Government organisation / Universities (academic only)
- Alternative name(s)
- University College London in United Kingdom, Collegium Universitatis Londinensis, UCL
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 01/02/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Stored in non-publicly available repository, Available on request |
| Publication and dissemination plan | The results of this study will be submitted for publication in a peer-reviewed academic journal, with a preference for journals focusing on clinical psychology, digital mental health, or eating disorders. Findings may also be shared through conference presentations, academic seminars, and research briefings. A plain language summary of the results will be made available to participants and relevant stakeholder groups, including mental health professionals and organisations supporting individuals with eating disorders. |
| IPD sharing plan | All personal data will be stored securely and handled in accordance with data protection regulations. De-identified individual participant data (IPD) may be shared with qualified researchers upon reasonable request from Dr Amy Harrison, a.harrison@ucl.ac.uk, following completion of the study and publication of the main results. Data will be pseudonymised to protect participant confidentiality, and requests will be reviewed by the research team to ensure appropriate use. Shared data will be limited to variables necessary for secondary analyses and will exclude any information that could directly or indirectly identify participants. Data sharing will be in line with GDPR and institutional ethics guidelines. Researchers requesting access will be required to submit a data use agreement. |
Editorial Notes
09/06/2025: Study's existence confirmed at the IOE PHD Doctoral Research Ethics Committee, Psychology and Human Development, UCL Institute of Education.
