📣 Help Shape the Future of UKRI's Gateway to Research (GtR)

We're improving UKRI's Gateway to Research and are seeking your input! If you would be interested in being interviewed about the improvements we're making and to have your say about how we can make GtR more user-friendly, impactful, and effective for the Research and Innovation community, please email gateway@ukri.org.

Windows of vulnerability: Sensitive periods for social adversity in adolescence

Lead Research Organisation: King's College London
Department Name: Psychology

Abstract

A large body of research has shown that adverse experiences during early childhood can affect children's development and have a lasting impact on their mental and cognitive health. This evidence suggests that the first few years of life form a window of vulnerability, or sensitive period, for adversity. This research has contributed to effective policy interventions designed to protect young children from adversity and improve their well-being. Inadvertently, the focus on early childhood has also led to a neglect of another formative period of our lives - adolescence.

Adolescence is characterized by protracted changes in brain structure and cognition. At the same time, young people experience profound changes in social roles. They become increasingly independent from their parents, and more focussed on peers. Emerging theories of adolescent development suggest that these social, cognitive and neural changes in adolescence may give rise to a second sensitive period after early childhood - particularly for adverse social experiences such as being bullied or excluded.

We are now at a unique point in time where recent advances in statistical methodology, combined with emerging data following large cohorts of young people over time, allow us to test these theories systematically. This provides unprecedented opportunities to foster well-being in young people by informing adversity prevention, detection and intervention efforts.

The three main objectives of our research are:

1. Identifying different types of social adversity

To capture the multifaceted nature of social adversity, we have established a partnership with the Children's Charity Barnardo's. We will be able to use their data on social, educational and mental health practitioners' views of what types of social adversity matter most to young people. Guided by these insights, we will analyse data from large UK cohorts to understand how different types of social adversity affect mental health and cognition in young people. We will feed our insights back to practitioners to help guide their practice and support young people who experience social adversity.

2. Characterizing windows of vulnerability in adolescence

Leveraging data from large UK cohorts, we will analyse how social adversity affects children, young people and adults. This will help us understand at what point in life what type of adversity affects us most. It will also tell us whether there are sensitive or vulnerable periods in adolescence. This work will help inform policy, charity and government work, by highlighting at what point in life prevention and intervention efforts may be most important.

3. Investigating developmental sequences

For this objective we will analyse data on young people's experience of adversity, as well as information on their cognitive and brain development. This will allow us to understand the sequence of developmental events leading from adversity to cognitive changes. This will generate new theories about sensitive periods in adolescence and inspire future research into adversity.

Our work will lead to a new understanding of vulnerabilities in young people. It will pinpoint what types of social adversity need to be targeted, and at which point in life, in order to ameliorate cognitive and mental health problems later on.

To ensure that our findings reach young people and those caring for them, we will write an accessible policy brief in partnership with Barnardo's, and host a collaborative workshop for practitioners, policy makers and charities. In this workshop, we will discuss our findings and seek input from stakeholders on how our findings synergize with policy and practice. We will then take our findings to the public through online, print and social media, as well as presenting our work in schools. All of this ensures that our work has a lasting and positive impact on young people's well-being.

Planned Impact

We propose to investigate vulnerabilities to social adversity in adolescence through a unique combination of user-guided qualitative research, and cutting-edge quantitative analyses using data from large cohorts of young people. The proposed research has implications that will influence a number of groups in wider society. Below we highlight the most relevant stakeholders and detail how they might benefit from this research. Please see the Pathways to Impact statement for a detailed discussion of how we propose to optimize user involvement and benefit to the wider society.

Young people

Most research on adversity to-date has focussed on young children. This research has contributed to improvements in wellbeing of children[15,17]. It has also inadvertently left later periods of development comparatively neglected[15,16]. Most of us have an intuitive sense that the teenage years were a formative period of our lives, during which social influences and adversity had a big impact on us. However, there is little formal research investigating how social adversity impacts young people. Our research will highlight the fact that society needs to engage with the difficulties and vulnerabilities young people face. This will be achieved through engaging practitioners and policy makers (see below). We will also take the science of adversity directly into schools and highlight sources of support to young people.

Educational, clinical and social practitioners

Through our partnership with Barnardo's, we will access data on practitioners' views of what types of adversity matter most. This data is not currently used systematically. We will analyse the surveys and feed our results back to Barnardo's through an accessible policy brief describing what types of adversity matter most, according to practitioners. The policy brief will also highlight how adversity relates to mental health and cognitive outcomes in UK cohorts and what types of adversity co-occur. In collaboration with Barnardo's we will identify and communicate how this evidence can be used to guide day-to-day practice.

Policy-makers and government

UNICEF and the Lancet commission "Our Future" (2016) argued that "Although evidence is building in some domains of adolescent's lives, greater understanding of the transition to adulthood and how different underlying factors interact is needed in order to inform the basis for effective programming and policy."[15]. To develop effective and evidence-based policies and interventions for social adversity in adolescence, we first need to determine A) What type of adversity impacts young people most and B) At what point in life these adversities have the largest impact. The proposed research will achieve this through a combination of participatory research and rigorous, quantitative analyses of large, representative cohorts. Findings will be shared with relevant stakeholders in a workshop so as to provide opportunities for dissemination and interactive discussion.

Publications

10 25 50
 
Description Our work has centred on three main objectives:

1. Identifying different types of social adversity in adolescence

To understand the nature of adolescents' adverse experiences, we have conducted two empirical studies (Pollmann et al., 2022; Kwok, Inman, et al., preprint) and produced a policy report with our charity partner Barnardo's (Inman et al., 2023). This work collectively highlights that family environment still matters in adolescence and that it is closely linked to mental health in early adulthood. In adolescence, school environments and abuse by a romantic partner are also important. This indicates that a broader set of adversities need to be considered for adolescence compared to childhood. This work culminated in an opinion piece (Pollmann et al., 2025), where we present a new framework for understanding Adverse Adolescent Experiences (AAEs). The framework builds on Bronfenbrenner's ecological systems theory to conceptualize adversities at intrapersonal, interpersonal, community and societal levels. We argue that this approach can enhance our understanding of adolescent adversity, facilitate the study of its potential effects, and guide prevention and intervention efforts.

2. Characterizing windows of vulnerability in adolescence

Leveraging data from the UK Understanding Society cohort, we are currently analysing how social adversity is linked to depression symptoms in young people aged 10-21 years old. This will help us understand at what point in adolescence social adversity affects us most. It will also tell us whether there are sensitive or vulnerable periods in adolescence. This work will help inform policy, charity, and government work, by highlighting at what point in adolescence prevention and intervention efforts may be most needed.


3. Investigating developmental sequences

Leveraging data from the American Adolescent Brain Cognitive Development (ABCD) cohort, we investigated the sequence of developmental events leading from adversity to mental health outcomes (Pollmann et al., 2024) and from puberty to social experiences and cortical development outcomes (Bates et al., preprint). This work collectively highlights that social experiences and brain development are linked, informing theories of adolescent development.

Additionally, we have been completing methodological work:

We have been completing methodological work to improve secondary data analysis and the study of adversity. First, we started a collaboration with the Danish Centre for Magnetic Resonance to develop analysis methods for high-temporal resolution neuroimaging data (see Fuhrmann, Skak Madsen et al., 2022). Second, we have written a review to improve secondary data analysis in Developmental Studies (Kievit et al., 2022). We also share analysis scripts for studies from the award and provide resources to the scientific community in the form of tutorials for complex analyses on our lab website (https://life-map-lab.com/about/).
Exploitation Route For academics, our work highlights that theories of childhood adversity may need to be extended to account for the complexity of adverse experiences in youth. To guide future research, we have developed a new framework for understanding adversity in adolescence (Pollmann et al., 2025). Our methodological work includes code and examples for modelling nonlinear trends in development (Fuhrmann, Skak Madsen et al., 2022), as well as guidelines and resources for improving secondary data analysis and modelling adversity across the lifespan (Kievit et al., 2022). We chaired a symposium on modelling environmental influences on developmental trajectories, bringing together methodologists in the field and sharing recommendations for best practices at the European Conference on Developmental Psychology 2023 (Turku, FIN). We also chaired a symposium on triangulating mixed methods to support causal inference and translation in developmental psychology at APS 2024 (San Francisco, CA ), providing showcases from the award and sharing best-practice recommendations for implementing mixed-methods research and research co-production.

Our work also contributes to making youth a priority for policy and practice. Our research highlights that society needs to engage with the difficulties and vulnerabilities young people face, which have become even more complex since the COVID-19 pandemic, as shown in our policy report (Inman et al., 2023). In the report, we also deliver recommendations for supporting vulnerable young people in the UK. We have also taken the science of adversity directly to young people. We worked with two youth advisors to create an animation detailing our research on adversity in an accessible and informative way (https://youtu.be/y82axD6PzEk?si=DiKMrnpE4EHLLiGC). This has been shared widely on social media by the teams and King's IoPPN platforms, with an accompanying article published on the IoPPN website (https://www.kcl.ac.uk/adversity-in-adolescence-research-insights-and-co-creation-with-young-people).
Sectors Communities and Social Services/Policy

Digital/Communication/Information Technologies (including Software)

Education

Other

URL https://life-map-lab.com/2023/10/29/sda-spa-project/
 
Description Our work has contributed to spotlighting youth as a priority for policy and practice. Our research highlights that society needs to engage with the difficulties and vulnerabilities young people face, which have become even more complex since the COVID-19 pandemic, as shown in our policy report (https://www.barnardos.org.uk/research/practitioners-concerns-issues-facing-young-people#:~:text=Poverty%2C%20financial%20instability%2C%20and%20inequality&text=They%20also%20reported%20that%20the,young%20people%2C%20particularly%20care%20leavers). In the report, we also deliver recommendations for supporting vulnerable young people in the UK. We have also taken the science of adversity directly to young people. We worked with two youth advisors to create an animation detailing our research on adversity in an accessible and informative way (https://youtu.be/y82axD6PzEk?si=DiKMrnpE4EHLLiGC). This has been shared widely on social media by the teams and King's IoPPN platforms, with an accompanying article published on the IoPPN website (https://www.kcl.ac.uk/adversity-in-adolescence-research-insights-and-co-creation-with-young-people). In 2025, we published a review in Nature Human Behaviour proposing a framework to better understand adolescent adverse experiences (https://www.nature.com/articles/s41562-024-02098-x). This review builds on studies across the award. It draws together research across multiple domains of adversity, from interpersonal to societal, and demonstrates the importance of recognising the developmental specificity and complexity of adolescence. We expect the review to stimulate systematic research into adolescent adversities to guide prevention and intervention efforts, informing policy and practice.
First Year Of Impact 2022
Sector Communities and Social Services/Policy,Education
Impact Types Societal

Policy & public services

 
Description Parliamentary briefing on the Barnardo's children's charity report (Inman et al., 2023)
Geographic Reach National 
Policy Influence Type Citation in other policy documents
 
Description Symposium at European Congress of Developmental Psychology, Turku, FIN, 2023: Modelling environmental influences on developmental trajectories
Geographic Reach Europe 
Policy Influence Type Influenced training of practitioners or researchers
Impact The symposium was well-attended. We provided practical guidance on the theory and implementation of sensitive period models and chaired an interdisciplinary discussion that stimulated research in the field and new collaborations.
URL https://sites.utu.fi/ecdp2023/programme/detailed-programme/
 
Description Symposium at the Association for Psychological Science (APS) Meeting in San Francisco, CA, 2024: Triangulating mixed methods to support causal inference and translation in developmental psychology
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact The symposium brought together methodologists across developmental psychology. It discussed best practices in mixed methods research, showcased UKRI-funded projects, and provided guidance for implementation.
URL https://www.psychologicalscience.org/conventions/2024-aps-annual-convention
 
Description Capturing loneliness across youth: Co-production of a new developmentally sensitive scale
Amount £883,222 (GBP)
Funding ID MR/X002381/1 
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 01/2023 
End 12/2025
 
Description Developing and Evaluating a Stepped Change Whole-University approach for Student Wellbeing and Mental Health
Amount £3,819,281 (GBP)
Funding ID MR/W002442/1 
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 08/2021 
End 08/2025
 
Description KCL Wellcome Trust Small Public Engagement Grant
Amount £1,000 (GBP)
Organisation King's College London 
Sector Academic/University
Country United Kingdom
Start 02/2022 
End 04/2022
 
Description King's Undergraduate Research Fellowship
Amount £1,222 (GBP)
Organisation King's College London 
Sector Academic/University
Country United Kingdom
Start 03/2022 
End 08/2022
 
Description NIHR Pre-Doctoral Fellowship
Amount £90,870 (GBP)
Funding ID NIHR303447 
Organisation National Institute for Health and Care Research 
Sector Public
Country United Kingdom
Start 08/2023 
End 02/2025
 
Description The time of their lives? Developing Concepts and Methods to Understand Loneliness in Students
Amount £843,960 (GBP)
Funding ID MR/X002810/1 
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 01/2023 
End 12/2025
 
Description Travel grant
Amount £1,000 (GBP)
Organisation Guarantors of Brain 
Sector Charity/Non Profit
Country United Kingdom
Start 11/2022 
End 11/2022
 
Description Travel grant for APS 2024
Amount £500 (GBP)
Organisation King's College London 
Sector Academic/University
Country United Kingdom
Start 04/2024 
End 05/2024
 
Description Travel grant to APS 2024
Amount £1,000 (GBP)
Organisation Guarantors of Brain 
Sector Charity/Non Profit
Country United Kingdom
Start 04/2024 
End 05/2024
 
Description UNITE: Understanding individual and social pathways to loneliness in young people from socio-economically marginalised backgrounds
Amount £810,663 (GBP)
Funding ID ES/X006026/1 
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 08/2023 
End 08/2026
 
Title Adapting non-linear mixed models for cognitive neuroscience research 
Description For our paper, Fuhrmann, Skak Madsen et al., 2022, NeuroImage, we adapted analysis code, originally developed for pharmacological data, for the analysis of neuroimaging data. 
Type Of Material Data analysis technique 
Year Produced 2022 
Provided To Others? Yes  
Impact We presented the methodology at a conference (FLUX, 2022) and are currently using it to model sensitive periods in youth. 
URL https://osf.io/cw8t2/
 
Title Developing Network Analysis as a tool for modelling adversity 
Description We have published code for network analyses of adverse experiences published in Pollmann et al. (2022): https://networksofadversities.netlify.app/. This was a novel application of the analysis method. We have also published a tutorial accompanying the paper: https://www.aylapollmann.com/methods-and-code/network-analysis 
Type Of Material Data analysis technique 
Year Produced 2022 
Provided To Others? Yes  
Impact This has been cited in: Lacey R. Network Analysis as an Emerging Method in Adversity Research - a Reflection on Pollman et al. (2022). Res Child Adolesc Psychopathol. 2023 Dec;51(12):1785-1787. doi: 10.1007/s10802-023-01063-y. Epub 2023 Apr 10. PMID: 37036583. 
URL https://www.aylapollmann.com/methods-and-code/network-analysis
 
Description Policy collaboration with Barnardo's Charity 
Organisation Barnardo's
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Dr Kathryn Bates led a team of research students to produce a public-facing report and parliamentary briefing for Barnardo's. We analysed qualitative data from Barnardo's quarterly practitioner survey and responses to questions on practitioners' emerging concerns for young people and what they thought the biggest issue young people had to face. We analysed 10 waves of data collected at quarterly intervals between June 2019 to November 2021 to understand what were main issues affecting young people and how had these changes over time. The findings of our report demonstrated that issues spanned structural (e.g., limited housing, government cuts to services), social (e.g., exposure to risk online, family issues) and individual levels (e.g., uncertainty and mental health issues). We also presented a call to action: tangible actions points to be presented to policymakers, such as reinstating community support for families and extending the age of discharge from child and adolescent mental health support services from 18 years old to 25 years old.
Collaborator Contribution The Barnardo's research team provided the data for analysis, support for completing the Barnardo's ethics application, as well as feedback on the research findings and written report. Prior to writing the report, we presented the research findings to the research team, policy team and Barnardo's chief officer. They provided discussion and feedback, which we integrated into the write up of the report. Dr Kathryn Bates has worked closely with the policy team who have supported editing the report, writing the parliamentary briefing and liaising with Barnardo's and KCL Press teams. The policy team will manage distribution of the report and parliamentary briefing.
Impact Through our collaboration we have produced a public-facing report on practitioners' perspectives of the key issues most affecting young people from June 2019-November 2021: Inman, A., Chen, S., Contini, E., Orben, A., Kievit, R., Kulbayeva, Z., Shah, M., Pollmann, A., Fuhrmann, D., Bates, K. E. (2023), "I am concerned about young people's mental health and that they have less hope for their future.": Practitioners' emerging concerns for young people between June 2019 to November 2021, Barnardo's Children's Charity. https://www.barnardos.org.uk/practitioners-concerns-issues-facing-young-people
Start Year 2021
 
Description Research collaboration with Danish Centre for Magnetic Resonance 
Organisation Danish Research Centre for Magnetic Resonance (DRCMR)
Country Denmark 
Sector Academic/University 
PI Contribution DF and RK initiated this collaboration to develop analysis methods for modelling high temporal resolution longitudinal data, in preparation for Study 2. The study culminated in a publication (Fuhrmann, Skak Madsen et al., 2022, NeuroImage). DF developed and implemented the analysis plan, with feedback from RK. All authors contributed to the writing of the paper. We are currently preparing another project with them, to do further analyses of their data.
Collaborator Contribution Our partners provided the longitudinal data necessary for the study and processed the imaging data. They fed back on the analysis and contributed to the write-up of the study.
Impact Fuhrmann, D., Skak Madsen, K., Baruël Johansen, L., Baaré, W. F. C., & Kievit, R. A. (2022). The midpoint of cortical thinning between late childhood and early adulthood differs between individuals and brain regions: Evidence from longitudinal modelling in a 12-wave neuroimaging sample. NeuroImage, 261, 119507. doi: 10.1016/j.neuroimage.2022.119507
Start Year 2021
 
Description Research collaboration with Dunn Lab at Harvard University 
Organisation Harvard University
Country United States 
Sector Academic/University 
PI Contribution Dr Kathryn Bates (postdoc on current award) and Dr Theresa Cheng (postdoc in the Dunn Lab) organised a scientific meeting with the Dunn Lab. This involved a day of talks and collaborative meetings between members of the Dunn Lab and Dr Delia Fuhrmann's research group: the Development and Environment Research Group (DERG). The Dunn Lab specialise in understanding the impact of adversity on development in childhood, we specialise in understanding the impact of adversity on development in adolescence. We shared insights and expertise on their research findings and future projects, and we presented a research proposal for our next project for feedback.
Collaborator Contribution The Dunn Lab specialise in methods to examine sensitive periods of development. We presented our proposal for our project modelling sensitive periods in mental health and the impact of adversity. The Dunn Lab offered expertise on how to model sensitive period of environmental exposure in longitudinal data. Moving forward, we will arrange bi-monthly meetings to discuss research methodology and research findings. The Dunn Lab collaboration will enhance the methodological and theoretical contributions of this project.
Impact This project is ongoing and there no outputs as of yet.
Start Year 2021
 
Description Adversity in adolescence 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Keynote talk given to "Bring your lunch" session
Year(s) Of Engagement Activity 2023
 
Description Adversity in adolescence: Research insights and co-creation with young people 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We wrote an article with one of our youth advisors summarising our research findings and experiences working with youth advisors for a King's IoPPN blog.
Year(s) Of Engagement Activity 2024
URL https://www.kcl.ac.uk/adversity-in-adolescence-research-insights-and-co-creation-with-young-people
 
Description Future Leaders UK Careers Evening Talk 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact I participated in a careers evening hosted by Future Leaders UK, a community action project in London. I talked about our ongoing research and spoke about careers in STEM with young people.
Year(s) Of Engagement Activity 2024
URL https://www.linkedin.com/feed/update/urn%3Ali%3Aactivity%3A7171406920639987712/?midToken=AQE8TxX2ce3...
 
Description How can we meaningfully involve young people in research? 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact 60-70 college students visited King's through the widening participation programme. Kathryn hosted an interactive session explaining the research process and facilitating discussion how young people can contribute towards research.
Year(s) Of Engagement Activity 2024
 
Description Invited keynote talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact I gave an invited keynote to a broad audience of scientists as well as practitioners in adolescent wellbeing
Year(s) Of Engagement Activity 2022
URL https://brainanddevelopment.nl/l-cid-congress-lessons-learned-and-future-lookouts/
 
Description Lecture series on current isssues in quantitative methods in psychology 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact The lecture series includes work from several UKRI projects to showcase best practices in Secondary Data Analysis and Research Co-Production
Year(s) Of Engagement Activity 2023,2024
 
Description Understanding adversity in adolescence 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We created an animation with our youth advisors to explain research findings on adversity in adolescence to a general public and young person audience in an accessible and informative format.
Year(s) Of Engagement Activity 2024
URL https://www.youtube.com/watch?v=y82axD6PzEk&t=1s
 
Description Understanding adversity in adolescence 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We created an animation explaining our adversity research with two youth and advisors and a design team.
Year(s) Of Engagement Activity 2024
URL https://www.youtube.com/watch?v=y82axD6PzEk
 
Description Widening participation activity (KCL Youth Awards) 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact DF co-organised the KCL Youth Awards for the KCL Psychology department. This included recruiting and hosting A-level students from local schools at KCL, and introducing them to research methods in Psychology.
Year(s) Of Engagement Activity 2021,2022,2023
URL https://www.kcl.ac.uk/ioppn/youth-awards/previous-ioppn-youth-award-winners