In the UK, 3 million children are living with a parent with depression or anxiety. These children are 3 times more likely to develop a mental health problem themselves, putting them at risk of later unemployment, physical health problems, and early mortality. This intergenerational cycle of mental illness is partly because children inherit genetic susceptibility to mental illness from their parents, but largely because of the environmental effects of living with a mentally unwell parent. To prevent future generations of children from developing mental illness and experiencing life-limiting consequences, we urgently need to understand how to break this intergenerational cycle. My research will address this by identifying environmental factors that affect whether mental health problems are passed on from parents to children. For example, I will test whether socioeconomic advantage (such as high family income and high levels of parental education) can interrupt the intergenerational cycle of mental health problems. I will also test whether the intergenerational cycle of mental illness is perpetuated by adverse family environments (e.g., child maltreatment, parental conflict, or parent substance abuse), and mitigated by positive social relationships (e.g., family social support, parent-child bond). To answer these questions, I will use large datasets of parents and children from the UK, Norway, Denmark, and the USA. My specific focus will be on parental depression and anxiety (the most common parental disorders) and their effects on child emotional and behavioural problems, which are well established. I will apply cutting-edge research designs and statistical techniques that can show whether environmental factors causally affect the intergenerational cycle of mental illness. For example, to understand the impact of income, I will test whether a cash-transfer intervention reduces the likelihood that parental mental illness is passed onto children. And to understand the impact of parental education, I will test whether the association between parent and child mental illness is mitigated when parents complete extra years of education due to a national education reform policy. These are just two examples of many methods that I will use to examine the causal effects of environmental factors on the intergenerational cycle of mental illness. By examining whether the findings are similar across different research methods, I will draw robust conclusions about which environmental factors can break the intergenerational cycle of mental illness. Crucially, I will use my findings to highlight modifiable targets for interventions to break the intergenerational cycle of mental illness. For example, if high income is found to mitigate the effects of parent mental illness on children's mental health, then economic interventions such as cash-transfers, tax-breaks, or an increased living wage could be employed to prevent at-risk children from developing mental illness. In addition, if unsafe family environments help explain the impact of transmission, then interventions to improve the family environment such as parenting support programmes could be adopted to help break the intergenerational cycle. To ensure that this research has societal impact, I will involve non-academic partners throughout the project, including policymakers from the Department of Health, clinicians, practitioners, and charities. I will also involve young people with lived experience of personal/parental mental illness throughout the research, to ensure benefit for patients. To share findings and co-design interventions to interrupt intergenerational transmission, I will hold a policy workshop with key stakeholders. I will also work with the Centre for Mental Health to conduct an economic evaluation on the cost effectiveness of interventions to interrupt transmission, and present findings to policymakers to convince them to invest in preventative interventions.

PROJECT APPROACH The C-STACS project will bring citizen science approaches to mental health. CHALLENGE: CITIZEN SCIENCE IS NEW TO MENTAL HEALTH Citizen science approaches have not yet been used at scale in mental health. We reviewed citizen science platforms. UK-based Zooniverse has no active, paused or finished mental health-related projects. EU-based eu-citizen.science has one project (CoAct) which includes mental health as one of several global concerns being addressed. USA-based scistarter.org has one project (neureka) using gamification for dementia research. The citizen science projects related to health which do exist typically involve biological and physical health research (e.g. www.cellslider.net, 100forParkinsons App, Colony B App). A more general internet search for citizen science and mental health identifies a few specific studies, e.g. the Emotional Brain Study addressing neuropsychological aspects of mental health and the MH2K Oldham project involving a youth-led approach to mental health, both in the UK, and the Games X Mental Health study exploring interactions between people with mental health problems and their informal carers in Spain. Two citizen science projects have taken place in the UK in relation to the overlapping area of wellbeing: the Secrets of Happiness study which ran in 2018 and has not published results, and the Great British Wellbeing Survey running in 2020. In relation to new projects, no mental health studies were funded as a UKRI Citizen Science Exploration Grant. Turning to publications, again very little has been written about citizen science and mental health. The 2020 ECSA report on characteristics of citizen science provides a useful foundation but no mental health specific guidance. A 2020 overview report by RAND Europe on emerging developments in citizen science identified the potential for new types of health research, such as personal health tracking / n-of-1 studies, but with no mention of mental health. A 2018 paper (https://doi.org/10.1093/heapro/daw086) on citizen science applied to public health provides a useful typology of project characteristics: Aims (investigation, education, collective good, action), Approaches (extreme, participatory science, distributed intelligence, crowd sourcing) and Size (local, mass). Our project will be mass participatory science, with aims of collective good (WP2) and action (WP3). Other papers have used citizen science in cognate areas, e.g. urban stress (https://doi.org/10.1057/s41599-020-0460-1). A 2019 position paper locates citizen science in relation to health research (https://doi.org/10.1080/15265161.2019.1619859), noting the connection with participatory action research and community-based participatory research traditions, and identifies community-driven 'n-of-we' studies which align with the current proposal. The paper also discusses general ethical issues of citizen science in health research, including consent, participation risks/benefits, data ownership and attribution, which have informed the WP1 focus on these issues. Finally, a search of the 'Citizen Science' journal identified one paper (https://doi.org/10.5334/cstp.184) discussing patient partners in health research. WORK PACKAGES (WPs) WP1 develops a theoretical foundation for citizen science in mental health, and prepares for WP2 and WP3. Mental health has a very established tradition of public involvement, coproduction and peer-led research, and mapping between mental health and citizen science constructs will be a key project output. WPs 2 and 3 address specific challenges outlined in the case for support, using Zooniverse as an online platform to support mass participation. WP2 creates new knowledge about supporting mental health recovery and WP3 about how people living with mental health problems actually look after themselves. WP4 mobilises the findings from WPs 1 to 3 to maximise impact.

Over the coming decades the world will face a wide range of complex, new and persistent public mental health challenges, exacerbated by disruptive events, many of which can be fully addressed only through strategies and investments that improve lifelong public mental health outcomes for everyone. 1 in 6 adults in England have a common mental health condition. Mental distress and ill health are associated with significant disability, sickness absence, unemployment, and suicide attempts. Three quarters of all mental health conditions have occurred in young people by the age of 24 years. Despite widespread acknowledgement that mental distress and illness make a substantial contribution to the global burden of disease, there is still a major gap in evidence to inform policy making for their primary prevention. We will establish the 'Prevention of Risks and Onset of Mental Health problems through Interdisciplinary Stakeholder Engagement' (PROMISE) Population Mental Health Improvement Cluster, which will create new opportunities for population-based improvements in mental health. We will focus on three challenge areas: 1. Children and young people; 2. Suicide and self-harm prevention; 3. Multiple long-term conditions. Challenge areas will be supported by four cross-cutting themes: 1. Partners in policy, implementation and lived experience; 2. Data, linkages and causal inference; 3. Narrowing inequalities; 4. Training and capacity building. We will work with stakeholders across public health, local government, voluntary organisations and interdisciplinary academic experts, and people with lived experience of adversities which impact mental health, to identify and rigorously evaluate population-level interventions which hold the greatest promise for the improvement of mental health. The structure of our cluster reflects the integration of academic, policy and lived experience in leadership and delivery, which will lead to systems change and the ability to work effectively across traditional silos which have held progress in this area behind. We will use a range of large-scale datasets, including representative studies which follow people over time, nationally representative studies of health, and data generated when people come into contact with health and other services, take part in census, alongside information from children in schools, and the linkages between these, for our investigations. We will use statistical methods in this data to understand which population-interventions benefit people's mental health and reduce inequalities. We will draw on the wide-ranging interdisciplinary expertise of our team to develop a unique suite of training (seminars/ tutorials/ short training videos) which will be freely available, the training will be entitled "New ways of working in population mental health" and will cover a range of topics useful to researchers, practitioners, and people with lived experience. Our cluster will foster methods to develop creative and innovative solutions by working with people who have not applied their expertise to improving population health before, through a range of approaches:1. We will work with arts-based practitioners to develop creative outputs (films, children's books/ comic strips, animations, infographics, public photography and art exhibitions), which will also ensure inclusive engagement. 2. We will convene a series of interdisciplinary 'sandpit' events to engage a wide range of interdisciplinary groups, to develop innovative projects across challenge areas. 3. We will convene policy roundtables with support from English, Scottish, Welsh and Northern Ireland Government representatives, to bring together stakeholders, experts, policymakers, and the public to engage in discussion on cluster challenges to gather feedback, build consensus, and develop actionable recommendations. Our findings will be co-produced with people with lived experience.

We will work with young people to use digital technology to transform adolescent mental health and provide a safe, and supportive, digital environment to tackle the unmet need arising from mental health disorders in those aged 10-24 years old. We are facing a youth mental health crisis; in the UK, one in eight young people have a mental health disorder, and one in four young women aged 17-19 have significant depression or anxiety with half of those having self-harmed; non-suicidal self-harm has nearly tripled over the past 10 years, while suicide rates per 100,000 adolescents have almost doubled. However, less than a third of all young people with mental health disorders receive any treatment. Many mental health and wellbeing apps exist, but most have no evidence base and some could even be harmful. Meanwhile, few research-based digital interventions have been shown to have impact in the real world. The youth mental health crisis has coincided with huge changes in society with creation of the 'digital environment' where being online and using social media has become central to young people's lives. While social media can be a helpful place for accessing information, exchanging views and receiving support, it has also been linked with depression, suicide and self-harm. Yet not all young people are at risk of mental health problems with social media we don't yet understand why some young people are more vulnerable than others. The COVID-19 crisis has been associated with increased mental health problems and greater online activity in young people. While their need to access trusted support online is greater than ever, social media platforms are not designed to meet mental health needs of young people. Aims & objectives. We will work with young people in our Young Person Advisory Group to: 1. increase understanding of the relationship between digital risk, resilience and adolescent mental health. 2. develop and evaluate preventative and personalised digital interventions. We aim to: - identify risk and resilience factors related to troublesome online experiences and activities, to prevent or reduce the emergence of depression, anxiety, and self-harm in young people. - understand how individual differences affect digital engagement (e.g. with social media and games) and adolescent brain and psychosocial development. - build, adapt and pilot new a generation of personalised and adaptive digital interventions incorporating a mechanistic understanding of human support with a new digital platform for delivery and trials in adolescent mental health conditions. - develop and test a novel socially assistive robot to help regulate difficult emotions with a focus on adolescents who self-harm. - develop and test a new digital tool to help adolescents better manage impulsive and risky behaviour with a focus on reducing the risk of self-harm. Applications & benefits. This work will translate new knowledge into practical tools to support young people negotiate the digital world, develop resilience and protect their mental health. Our involvement of young people means that the outputs from the research will be suitable and meaningful. Young people will be actively involved shaping the research at all stages. Young people, their caregivers, teachers, clinicians and charities will benefit from a range of co-created apps and tools to manage youth mental health issues. Young people will benefit from research training offered as part of their involvement. Policy makers and academics will benefit from new understandings of risk and resilience in the digital world to support novel interventions and evidence-based policy. Our work will establish a new, ethical and responsible way of designing digital platforms and tools that supports young people's mental health. Our Mental Health & Digital Technology Policy Liaison Group and Partners Board will translate our research into a step-change in mental health outcomes.