Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools

Victoria Pile; Rose Tinch-Taylor; Ben Carter; Jessica Richardson; Lisa de Rijk; Mary Leamy; Simon E. Blackwell; Richard Meiser-Stedman; Barnaby D. Dunn; Sarah Byford; Emily A. Holmes; Cathy Creswell; Patrick Smith

doi:10.1186/s13063-025-08920-9

Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools

Victoria Pile, Rose Tinch-Taylor, Ben Carter, Jessica Richardson, Lisa de Rijk, Mary Leamy, Simon E. Blackwell, Richard Meiser-Stedman, Barnaby D. Dunn, Sarah Byford, Emily A. Holmes, Cathy Creswell, Patrick Smith

Research output: Contribution to journal › Article › peer-review

Abstract

Background: There is an urgent need for psychological interventions that can target depression in late adolescence and prevent it from having lifelong implications. Schools have been identified as a promising setting to enhance access to interventions and offer support earlier. We have co-developed a novel intervention, IMAGINE, that targets key cognitive mechanisms implicated in depression across the lifespan. Depression has been associated with distressing negative mental images, a deficit in positive future images and overgeneral autobiographical memories. Interventions targeting these factors have shown clinical promise in adults. Here, we combine techniques targeting these cognitive processes into a novel, brief psychological intervention for adolescent depression. This Phase IIb randomised controlled trial will evaluate IMAGINE compared to an active psychological intervention.

Methods/design: One hundred sixty adolescents (aged 16–18) with high levels of depressive symptoms will be recruited from schools. Participants will be randomly allocated to IMAGINE or the active psychological control intervention, non-directive support (NDS). Assessment will take place at baseline, 8-, 16- and 24-week post randomisation. The primary objective is to establish whether IMAGINE reduces symptoms of depression, relative to NDS, at 8 weeks following randomisation. Secondary objectives include whether changes in depression are maintained at 16- and 24-week follow-up, the efficacy of IMAGINE on secondary clinical outcomes and key cognitive mechanisms and, finally, to assess outcomes around acceptability, safety and adherence.

Discussion: If IMAGINE is shown to be safe and clinically effective, an effectiveness-implementation hybrid RCT will be indicated. If rolled out as an intervention, IMAGINE would significantly extend the range of effective therapies available for adolescent depression.

Trial registration: ISRCTN, ISRCTN14015295. Registered 11 September 2023, https://doi.org/10.1186/ISRCTN14015295.

Original language	English
Article number	236
Journal	Trials
Volume	26
DOIs	https://doi.org/10.1186/s13063-025-08920-9
Publication status	Published - 3 Jul 2025

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Cite this

Pile, V., Tinch-Taylor, R., Carter, B., Richardson, J., de Rijk, L., Leamy, M., Blackwell, S. E., Meiser-Stedman, R., Dunn, B. D., Byford, S., Holmes, E. A., Creswell, C., & Smith, P. (2025). Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools. Trials, 26, Article 236. https://doi.org/10.1186/s13063-025-08920-9

@article{92372a53fd30414b9f5caedcd3e8b0bf,

title = "Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools",

abstract = "Background: There is an urgent need for psychological interventions that can target depression in late adolescence and prevent it from having lifelong implications. Schools have been identified as a promising setting to enhance access to interventions and offer support earlier. We have co-developed a novel intervention, IMAGINE, that targets key cognitive mechanisms implicated in depression across the lifespan. Depression has been associated with distressing negative mental images, a deficit in positive future images and overgeneral autobiographical memories. Interventions targeting these factors have shown clinical promise in adults. Here, we combine techniques targeting these cognitive processes into a novel, brief psychological intervention for adolescent depression. This Phase IIb randomised controlled trial will evaluate IMAGINE compared to an active psychological intervention. Methods/design: One hundred sixty adolescents (aged 16–18) with high levels of depressive symptoms will be recruited from schools. Participants will be randomly allocated to IMAGINE or the active psychological control intervention, non-directive support (NDS). Assessment will take place at baseline, 8-, 16- and 24-week post randomisation. The primary objective is to establish whether IMAGINE reduces symptoms of depression, relative to NDS, at 8 weeks following randomisation. Secondary objectives include whether changes in depression are maintained at 16- and 24-week follow-up, the efficacy of IMAGINE on secondary clinical outcomes and key cognitive mechanisms and, finally, to assess outcomes around acceptability, safety and adherence. Discussion: If IMAGINE is shown to be safe and clinically effective, an effectiveness-implementation hybrid RCT will be indicated. If rolled out as an intervention, IMAGINE would significantly extend the range of effective therapies available for adolescent depression. Trial registration: ISRCTN, ISRCTN14015295. Registered 11 September 2023, https://doi.org/10.1186/ISRCTN14015295.",

author = "Victoria Pile and Rose Tinch-Taylor and Ben Carter and Jessica Richardson and {de Rijk}, Lisa and Mary Leamy and Blackwell, {Simon E.} and Richard Meiser-Stedman and Dunn, {Barnaby D.} and Sarah Byford and Holmes, {Emily A.} and Cathy Creswell and Patrick Smith",

note = "Data availability: It is intended that the anonymised dataset will be made publicly available following the completion of the trial. Funding Information: Dr. Victoria Pile (Advanced Fellowship, NIHR301312) is funded by the NIHR for this research project. CC receives funding from the Oxford Health NIHR BRC and the Oxford and Thames Valley NIHR ARC. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR, NHS or the UK Department of Health and Social Care.",

year = "2025",

month = jul,

day = "3",

doi = "10.1186/s13063-025-08920-9",

language = "English",

volume = "26",

journal = "Trials",

issn = "1745-6215",

publisher = "BioMed Central",

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Pile, V, Tinch-Taylor, R, Carter, B, Richardson, J, de Rijk, L, Leamy, M, Blackwell, SE, Meiser-Stedman, R, Dunn, BD, Byford, S, Holmes, EA, Creswell, C & Smith, P 2025, 'Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools', Trials, vol. 26, 236. https://doi.org/10.1186/s13063-025-08920-9

TY - JOUR

T1 - Evaluating a brief imagery-based intervention for adolescent depression: Study protocol for a phase IIB randomised control trial (INDIGO) in secondary schools

AU - Pile, Victoria

AU - Tinch-Taylor, Rose

AU - Carter, Ben

AU - Richardson, Jessica

AU - de Rijk, Lisa

AU - Leamy, Mary

AU - Blackwell, Simon E.

AU - Meiser-Stedman, Richard

AU - Dunn, Barnaby D.

AU - Byford, Sarah

AU - Holmes, Emily A.

AU - Creswell, Cathy

AU - Smith, Patrick

N1 - Data availability: It is intended that the anonymised dataset will be made publicly available following the completion of the trial. Funding Information: Dr. Victoria Pile (Advanced Fellowship, NIHR301312) is funded by the NIHR for this research project. CC receives funding from the Oxford Health NIHR BRC and the Oxford and Thames Valley NIHR ARC. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR, NHS or the UK Department of Health and Social Care.

PY - 2025/7/3

Y1 - 2025/7/3

N2 - Background: There is an urgent need for psychological interventions that can target depression in late adolescence and prevent it from having lifelong implications. Schools have been identified as a promising setting to enhance access to interventions and offer support earlier. We have co-developed a novel intervention, IMAGINE, that targets key cognitive mechanisms implicated in depression across the lifespan. Depression has been associated with distressing negative mental images, a deficit in positive future images and overgeneral autobiographical memories. Interventions targeting these factors have shown clinical promise in adults. Here, we combine techniques targeting these cognitive processes into a novel, brief psychological intervention for adolescent depression. This Phase IIb randomised controlled trial will evaluate IMAGINE compared to an active psychological intervention. Methods/design: One hundred sixty adolescents (aged 16–18) with high levels of depressive symptoms will be recruited from schools. Participants will be randomly allocated to IMAGINE or the active psychological control intervention, non-directive support (NDS). Assessment will take place at baseline, 8-, 16- and 24-week post randomisation. The primary objective is to establish whether IMAGINE reduces symptoms of depression, relative to NDS, at 8 weeks following randomisation. Secondary objectives include whether changes in depression are maintained at 16- and 24-week follow-up, the efficacy of IMAGINE on secondary clinical outcomes and key cognitive mechanisms and, finally, to assess outcomes around acceptability, safety and adherence. Discussion: If IMAGINE is shown to be safe and clinically effective, an effectiveness-implementation hybrid RCT will be indicated. If rolled out as an intervention, IMAGINE would significantly extend the range of effective therapies available for adolescent depression. Trial registration: ISRCTN, ISRCTN14015295. Registered 11 September 2023, https://doi.org/10.1186/ISRCTN14015295.

AB - Background: There is an urgent need for psychological interventions that can target depression in late adolescence and prevent it from having lifelong implications. Schools have been identified as a promising setting to enhance access to interventions and offer support earlier. We have co-developed a novel intervention, IMAGINE, that targets key cognitive mechanisms implicated in depression across the lifespan. Depression has been associated with distressing negative mental images, a deficit in positive future images and overgeneral autobiographical memories. Interventions targeting these factors have shown clinical promise in adults. Here, we combine techniques targeting these cognitive processes into a novel, brief psychological intervention for adolescent depression. This Phase IIb randomised controlled trial will evaluate IMAGINE compared to an active psychological intervention. Methods/design: One hundred sixty adolescents (aged 16–18) with high levels of depressive symptoms will be recruited from schools. Participants will be randomly allocated to IMAGINE or the active psychological control intervention, non-directive support (NDS). Assessment will take place at baseline, 8-, 16- and 24-week post randomisation. The primary objective is to establish whether IMAGINE reduces symptoms of depression, relative to NDS, at 8 weeks following randomisation. Secondary objectives include whether changes in depression are maintained at 16- and 24-week follow-up, the efficacy of IMAGINE on secondary clinical outcomes and key cognitive mechanisms and, finally, to assess outcomes around acceptability, safety and adherence. Discussion: If IMAGINE is shown to be safe and clinically effective, an effectiveness-implementation hybrid RCT will be indicated. If rolled out as an intervention, IMAGINE would significantly extend the range of effective therapies available for adolescent depression. Trial registration: ISRCTN, ISRCTN14015295. Registered 11 September 2023, https://doi.org/10.1186/ISRCTN14015295.

U2 - 10.1186/s13063-025-08920-9

DO - 10.1186/s13063-025-08920-9

M3 - Article

SN - 1745-6215

VL - 26

JO - Trials

JF - Trials

M1 - 236

ER -