Trial investigating the effects of a brief online uncertainty tolerance training for young people

ISRCTN	ISRCTN17157557
DOI	https://doi.org/10.1186/ISRCTN17157557
Open Science Framework	https://osf.io/6emyp
Sponsor	MRC Cognition and Brain Sciences Unit
Funder	MRC Cognition and Brain Sciences Unit

Submission date: 30/05/2026
Registration date: 02/06/2026
Last edited: 01/06/2026

Recruitment status: No longer recruiting
Overall study status: Ongoing
Condition category: Mental and Behavioural Disorders

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Adolescents and young adults have an increased vulnerability to mental health problems. Psychological problems in young people have also risen over the past few decades, which has in part been attributed to increased global uncertainty. Given the substantial uncertainties young people face in their daily lives, determining how to improve their ability to cope with uncertainty is essential.

This study aims to investigate the effects of Uncertainty-Mindset Training (UMT) for older adolescents/emerging adults (i.e., 18–24-year-olds). The UMT is a brief online informational program which aims to increase tolerance of uncertainty. The UMT will be compared to a control training to determine its effects on a range of outcomes up to 3 months later.

Who can participate?
Individuals aged 18 to 24 years with native English fluency and no history of traumatic brain injury, epilepsy/seizures, or learning difficulties. Participants will be recruited from Prolific, a platform that helps researchers recruit participants for their online research, and must have a 95-100% approval rate, have completed at least 20 prior studies but not one of the related studies run by the research team, and live in either the UK, US, Australia, New Zealand, Canada, Ireland, or South Africa.

What does the study involve?
Participants will be recruited from Prolific to complete the 4-part study. In part 1 (baseline, training, and immediately post-training), participants will first complete a set of questionnaires and a decision-making task. They will then be randomly allocated to complete either the Uncertainty-Mindset Training or Mind and Brain Training. This will be followed by another set of questionnaires. In part 2 (completed two weeks after part 1), participants will complete a set of questionnaires and decision-making task. In parts 3 and 4 (one and three months following part 1, respectively), participants will complete a set of questionnaires.

What are the possible benefits and risks of participating?
There is no guarantee that taking part will benefit any or all individuals. The training programs may increase knowledge about psychologically related processes, and participation could help us understand how to better help others. A potential risk of taking part is that participants may experience distress and worse mood when reflecting on their experiences whilst or after completing the questionnaires and/or the trainings, but participants can skip any questions and withdraw from the study at any point.

Where is the study run from?
The University of Cambridge, UK.

When is the study starting and how long is it expected to run for?
June 2026 and will run for approximately 3 months to October 2026.

Who is funding the study?
The MRC Cognition and Brain Sciences Unit, UK.

Who is the main contact?
Sarah Daniels, Sarah.Daniels@mrc-cbu.cam.ac.uk

Contact information

Ms Sarah Daniels
Public, Scientific

MRC Cognition and Brain Sciences Unit, 15 Chaucer Rd
Cambridge
CB2 7EF
United Kingdom

ORCID ID	0009-0003-8384-1867
Phone	+44 01223 767529
Email	Sarah.Daniels@mrc-cbu.cam.ac.uk

Prof Tim Dalgleish
Principal investigator

MRC Cognition and Brain Sciences Unit, 15 Chaucer Rd
Cambridge
CB2 7EF
United Kingdom

ORCID ID	0000-0002-7304-2231
Phone	+44 01223 767654
Email	Tim.Dalgleish@mrc-cbu.cam.ac.uk

Study information

Primary study design	Interventional
Allocation	Randomized controlled trial
Masking	Open (masking not used)
Control	Active
Assignment	Parallel
Purpose	Prevention, Treatment
Scientific title	A randomised controlled trial investigating whether the single session online Uncertainty-Mindset Training improves tolerance of uncertainty and anxiety symptoms greater than a control training in 18- to 24-year-olds
Study objectives	This study aims to investigate the effects of the Uncertainty-Mindset Training (UMT) for older adolescents/emerging adults (i.e., 18-24 year olds). Primarily, this study seeks to understand whether it reduces intolerance of uncertainty and anxiety symptoms. Secondarily, this study seeks to determine the effects of the UMT on depression symptoms, negative affect, and growth mindsets. Further, the study aims to examine whether changes in intolerance of uncertainty account for the effects of the UMT on mental health symptoms and negative affect.
Ethics approval(s)	Approved 06/05/2026, University of Cambridge Psychology Research Ethics Committee (Department of Psychology, Downing Street, University of Cambridge, Cambridge, CB2 3EB, United Kingdom; +44 01223 333550; SBSEthics@admin.cam.ac.uk), ref: PRE.2025.060
Health condition(s) or problem(s) studied	Reduction of intolerance of uncertainty and anxiety symptoms in an unselected population (i.e., with or without a psychiatric condition).
Intervention	Participants will be randomised in a 1:1 allocation to receive either the Uncertainty-Mindset Training or the control Mind and Brain Training. This will be done using the Qualtrics randomizer element with the even presentation setting. Uncertainty-Mindset Training: This approximately 30-minute online program presents information in text and video format about how uncertainty can be beneficial (aiming to promote uncertainty-as-adaptive mindsets and encouraging the reappraisal of uncertainty as not inherently negative but potentially useful), the malleability of uncertainty tolerance (aiming to promote uncertainty tolerance growth mindsets i.e., that IU can be improved through processes such as neuroplasticity), and strategies for facing uncertainty (e.g., goal setting, acceptance, reappraisal). Interactive free text questions are also dispersed throughout asking people about their personal experiences and to advise others about facing uncertainty. Mind and brain control training: This approximately 30-minute online program includes information on psychologically related topics about the brain and mind (e.g., cognitive biases, sleep, emotions, etc.). The information is also presented in text and video format, with interactive free text questions throughout asking people to recall presented information, provide examples, and share their thoughts on the program. This control training has been developed to not target tolerance of uncertainty.
Intervention type	Behavioural
Primary outcome measure(s)	Intolerance of uncertainty measured using the 12-item Intolerance of Uncertainty Scale (IUS-12) at 3 months Anxiety symptoms measured using the 7-item Generalised Anxiety Disorder Scale (GAD-7) at 3 months
Key secondary outcome measure(s)	Intolerance of uncertainty measured using the 12-item Intolerance of Uncertainty Scale (IUS-12) at baseline, immediately post-training, 2 weeks, and 1 month Anxiety symptoms measured using the 7-item Generalised Anxiety Disorder Scale (GAD-7) at baseline, 2 weeks, and 1 month Depression symptoms measured using the 8-item Patient Health Questionnaire (PHQ-8) at baseline, 2 weeks, 1 month, and 3 months Negative affect measured using two items (capturing distressed and anxious affect) at baseline, immediately post-training, 2 weeks, 1 month, and 3 months Growth mindsets about uncertainty tolerance measured using three novel items at baseline, immediately post-training, 2 weeks, 1 month, and 3 months Repetitive negative thinking measured using the 15-item Perseverative Thinking Questionnaire (PTQ) at baseline, 2 weeks, 1 month, and 3 months Uncertainty-related functioning measured using five items at baseline, 2 weeks, 1 month, and 3 months Affective responses to uncertainty across domains measured using the Affective Responses to Daily Uncertainty Scale (ARDUS) at baseline, 2 weeks, 1 month, and 3 months Uncertainty engagement measured using two items (capturing uncertainty reappraisal and avoidance) at baseline, 2 weeks, 1 month, and 3 months Uncertainty avoidance, exploration, and task-related mood measured using an explore-exploit foraging task at baseline and 2 weeks
Completion date	08/10/2026

Eligibility

Participant type(s)
Age group	Adult
Lower age limit	18 Years
Upper age limit	24 Years
Sex	All
Target sample size at registration	388
Key inclusion criteria	1. Aged 18-24 years 2. Native English fluency 3. No history of traumatic brain injury 4. No history of epilepsy/seizures 5. No learning difficulties 6. Live in one of the following countries: UK, US, Australia, New Zealand, Canada, Ireland, South Africa 7. 95-100% approval rate on Prolific 8. Minimum of 20 prior studies completed on Prolific 9. Not previously recruited for the related studies run by research team
Key exclusion criteria	1. Fail 2 or more attention checks at any assessment 2. Submit an exceptionally fast study response (3 SD or below the mean response time of the sample)
Date of first enrolment	08/06/2026
Date of final enrolment	08/07/2026

Locations

Countries of recruitment

United Kingdom
England
Australia
Canada
Ireland
New Zealand
South Africa
United States of America

Study participating centre

MRC Cognition and Brain Sciences Unit

15 Chaucer Rd
Cambridge
CB2 7EF
England

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan	The datasets generated during and/or analysed during the current study will be stored in a publicly available repository (OSF).

Editorial Notes

01/06/2026: Study’s existence confirmed by the University of Cambridge Psychology Research Ethics Committee, UK.