Editorial: Socio-economic inequality and child and adolescent mental health

It would be hard to find anyone, including politicians anywhere on the political spectrum, who would not agree that a society should look after its children well – giving them a good start in life, protecting their interests and their health and wellbeing, and promoting their development and education. Our children are our future – our long-term societal well-being depends on them. And there is widespread contemporary concern for the mental health of children and adolescents, following the global COVID-19 pandemic.

In this context, it is perhaps surprising that it is so difficult to compare different societies in terms of child and adolescent mental health, but it remains the case that there are no sources of high quality, internationally comparable data on mental illness in children and young people. Even within countries, there are surprisingly few sources of data – no data on child mental illness could be included in the recent Child and Adolescent Thriving Index 1.0 in the USA (Pickett, 2022). To try and understand both variation in child and adolescent mental health, and the causes of such variation, we have to use proxy measures, such as life satisfaction, or measures such as the adolescent suicide rate that represent a very extreme tip of an iceberg of mental distress. In their most recent report on child well-being in high income countries, the United Nations Children's Fund (UNICEF), created an index of mental well-being that includes the percentage of 15 year olds reporting high life satisfaction and the suicide rate for 15–19 year olds (https://www.unicef-irc.org/publications/pdf/Report-Card-16-Worlds-of-Influence-child-wellbeing.pdf). On this index, the Netherlands ranks top and New Zealand bottom, and there is much variation in both measures. Over 90% of children in the Netherlands have high life satisfaction, but only 64% of UK children say the same. In Greece, the teenage suicide rate is 1.4 per 100,000 adolescents, in New Zealand that figure is 10 times higher at 14.9 per 100,000.

Nevertheless, there are now a number of studies suggesting that income inequality, the gap between rich and poor in a society, is robustly associated with measures of mental well-being in children and young people (Alemán-Díaz et al., 2016), whether that is child mental illness in relation to income inequality across the 50 US states (Wilkinson & Pickett, 2009), happiness and psychological distress across regions of China (Du, Chi, & King, 2019) or psychological symptoms across 17 high income countries (Dierckens et al., 2020). We have also shown that changes in income inequality are related to changes in child well-being – as countries become more or less equal their child well-being rises or falls (Pickett & Wilkinson, 2015).

Within countries, socio-economic position has a well-described and profound impact on all aspects of child and adolescent mental health, creating social gradients and inequalities in everything from socio-emotional behaviour problems (Straatmann, Campbell, Rutherford, Wickham, & Taylor-Robinson, 2017) to schizophrenia (Hakulinen, Webb, Pedersen, Agerbo, & Mok, 2020). Even conditions long thought to be associated with affluence, such as eating disorders, present across the full range of socioeconomic backgrounds (Huryk, Drury, & Loeb, 2021). Figure 1 is a framework for visualising how socio-economic inequality between societies interacts with socio-economic position within societies, creating steeper social gradients in health outcomes. We need to be mindful of both influences when thinking about policy and practice solutions for child and adolescent mental health and health inequalities.

The pathways through which children and adolescents are sensitive to structural inequalities are complex and multi-faceted. Some of the pathways involve a lack of material resources, including access to care and treatment for mental health issues, but psychosocial factors are central. Our own explanatory theory is that inequality impacts the quality of social relations, shifting the balance between evolved social strategies for dealing with more stressful dominance relations or more supportive relationships based on reciprocity and cooperation. In more unequal societies, our sensitivity to status is heightened – social status and position become more salient making social comparisons more invidious, and status anxiety is increased (Layte & Whelan, 2014), with implications for psychological responses involving dominance (e.g., self enhancement, narcissism), submission (e.g., depression) or behaviours such as addictions.

Some of the pathways through which inequality affects children and adolescents are indirect, acting though the effects of inequality on parents, caregivers and other family members, (e.g., higher prevalence of their own mental health problems, longer working hours, higher levels of household debt) raising levels of chronic stress within families. Research has shown that the prevalence of child maltreatment is higher in more unequal societies. Inequality also affects children's own direct exposure to the impacts of inequality, for example, levels of bullying are higher and levels of generalised trust are lower (Wilkinson & Pickett, 2017, 2018).

Relations with peers have always been important for children and young people's mental well-being. The Wellcome Trust views social relations as an ‘active ingredient’ for mental health, recognising that for young people, in particular, social relationships can support them through critical stages of the formation of their social identities and offer resources that increase resilience to depression and anxiety. For today's children and young people, however, social relationships, including with peers, increasingly take place on digital platforms. Ninety-seven percent of young people use at least one social media platform. That exposes them more than any previous generation not just to cyber bullying, but to the judgements of other people, exactly the processes that can exacerbate status anxiety. Social media can also be a positive source of social contact for many young people and this support was helpful for many of them through the isolation they experienced during the COVID-19 pandemic; research findings on the impact of social media on the mental health of children and young people are very mixed, although a recent systematic review of 126 studies and a meta-analysis of 76 suggests an effect on adverse health-related behaviours among adolescents, such as alcohol and drug consumption (Purba, Henderson, Baxter, Katikireddi, & Pearce, 2023). We are not aware of any studies that have examined whether or not associations between social media use and mental well-being vary by societal income inequality, but this might be a fruitful area for future research.

Children and adolescents are not, of course, simply passive recipients of the broader social determinants that shape their mental health. How they perceive inequality, how they feel about their own and their family's social status within society also affects their mental health and well-being. Research shows that young people who perceive themselves as belonging to a poorer family than the families of their friends experience worse mental health and more interpersonal difficulties. Worryingly, increased sensitivity to inequality may actually make it more difficult to study these phenomena. In an ongoing cohort study of adolescents in the North of England, co-production work revealed a reluctance to self-report relative subjective social status, with young people expressing a dislike of being asked to compare themselves to others (Moss, Kelly, Bird, Nutting, & Pickett, 2023).

However, for those concerned with social justice, it is heartening to recognise that, while children and young adults may be suffering the consequences of inequality, they can also be important advocates for positive change. A recent UK study showed that young people were more likely than older people to be aware of, and concerned about, inequality. There are also positive examples across the world of young people participating as active citizens and campaigning against inequality (Bruselius-Jensen, Pitti, & Tisdall, 2021). Such participation may not only help to promote change but may also mitigate against the mental health impacts of inequality by giving young people social connections and a sense of solidarity, as well a sense of purpose and agency.

No ethical approval was required for this article.