Windows of vulnerability: Sensitive periods for social adversity in adolescence

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.

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.