Young people grow to adulthood within a complex web of familypeercommunitysocietaland cultural influences that affect present and future health and wellbeing. Over the past two decadestheorists have begun to argue that understanding and enhancing health needed a focus upstream from an individual's risk or protective factors to the social patterns and structures that shape people's chances to be healthy. Commonly referred to as the social determinants of health (SDH) approachsuch work focuses on the social contexts that affect health and also the pathways by which social conditions translate into health effects. In assessing the so-called causes of the causeswork on SDH particularly focuses on how the causes of individual problems relate to the causes of population incidencehow differences between individuals relate to differences between populationsand how social gradients and cultural factors affect health outcomes.1
WHO defines SDH as “the conditions in which people are borngrowlivework and age”conditions or circumstances that are shaped by families and communities and by the distribution of moneypowerand resources at globalnationaland local levels and affected by policy choices at each of these levels.1 The first report in this Series on adolescent health2 shows one model of the overlapping spheres of influence of social determinants on young peoplewhich could be elaborated to incorporate further positive influences and assets that support adolescent health. The health burden associated with operation of these SDHand the substantial potential for improving health through modifiable SDH is increasingly recognised by nations and international agencies. In 2008the report of the WHO Commission on Social Determinants of Health emphasised the importance of a life-course approach to action on SDH.1 Howeverlife-course approaches have thus far focused almost entirely on early childhood determinants of later adult health.34 Adolescenceas a key developmental stage in the life coursehas been neglected in SDH research.
Developmental theorists have long identified adolescence as a crucial period of psychological and biological changesecond only to early childhood in the rate and breadth of developmental change. During adolescencerapid development of the CNS and other biological systems interact with social development to entrain new behaviours and to allow many transitions important for an individual to function as a productive adult (panel 1). Approaches to problems in adolescent health have moved beyond traditional risk-factor reduction focused on the individual to emphasise the importance of enhancing protective factors in young people's lives. Such resiliency-based approaches have focused on family and peer factors as important in protecting young people from harmbut also emphasise that a successful and healthy transition to adulthood needs promotion of positive social and emotional development as much as avoiding drugsviolenceor sexual risk.6 Howeverdespite extensive published work on potentially malleable factors that act as risk and protective factors across a range of adolescent-health outcomes,7 there has been little systematic study of the effects of social determinants on adolescent health.
Key messages
- •
The social determinants of health are defined by the WHO Commission on the Social Determinants of Health as “the conditions in which people are borngrowlivework and age”; these conditions or circumstances are shaped by families and communities and by the distribution of moneypowerand resources at worldwidenationaland local levelsand affected by policy choices at each of these levels.
- •
Adolescence is a second sensitive developmental period in which puberty and rapid brain maturation lead to new sets of behaviours and capacities that trigger or enable transitions in familypeerand educational domainsand in health behaviours. These transitions modify childhood trajectories towards health and wellbeing.
- •
Our analyses show that the strongest determinants of adolescent health are structural factors such as national wealthincome inequalityand access to education. Furthermoresafe and supportive familiessafe and supportive schoolstogether with positive and supportive peersare crucial to helping young people develop to their full potential and attain the best health in the transition to adulthood.
- •
Improving adolescent health worldwide requires improving young people's daily lives with families and peers and in schoolsaddressing risk and protective factors in the social environment at a population leveland focusing on factors that are protective across various health outcomes.
- •
The most effective interventions are probably structural changes to improve access to education and employment for young people and to reduce the risk of transport-related injury. Other crucial aspects are ensuring participation of young people in policy and service developmentand building capacity in personnel and data systems in adolescent health.
Our objectives in this report are to review what is known about SDH in adolescenceto use original data to assess key determinants of adolescent healthand to extend existing life-course models of SDH to include adolescence.
Many models exist to explain the operation of social determinantsfrom levels proximal to the individualsuch as family or peersthrough communitiesto factors quite distal from the individualsuch as economic opportunities provided by the state. Since these models deal with “the conditions in which people are borngrowlivework and age”it is perhaps not surprising that published work contains competing models with a complex and inconsistent array of concepts and terms (panel 2). We will use the conceptual framework of the WHO Commission on Social Determinants of Health to identify two main levels at which determinants operate: structural and proximal.
Structural determinants are the fundamental structures that generate social stratificationsuch as global and national economicpoliticaland social welfare systemsand education systems. Proximalalso called intermediate, determinants are the circumstances of daily lifefrom the quality of the family environment and peer relationshipsthrough availability of foodhousingand recreationto access to education. Proximal determinants are generated by the social stratification that results from structural determinantsbut are also generated through culturalreligiousand community factors. These proximal determinants establish individual differences in exposure and vulnerability to health compromising factors that generate health or ill health.1 These levels closely correspond to environmental spheres of influence affecting a young personfrom family and peer groupto schoolto neighbourhoodand to wider society.4
Life-course theorists have identified three ways in which SDH might operate. Determinants that affect development in early life or experiences that affect adult health independent of intervening experience have been termed latent effects. Determinants that set individuals onto life trajectories that affect their healthwellbeingand competence over their life course can be understood as pathway effects. Cumulative effects refer to the accumulation of advantage or disadvantage due to exposure to unfavourable environments over time.8
We review existing data on the effects of structural and proximal SDHand their interactionson health in adolescence. We also present findings from a series of ecological analyses done with worldwide country-level data on the health of young people aged 10–24 years from publicly available UN agency sources. Studies of natural experiments such as variations in health outcomes between nations provide useful data on the effect of structural determinants on healthalthough ecological analyses cannot prove causation. They might also provide information on the operation of proximal determinants outside high-income countriesparticularly since the operation of determinants within countries is similar to those operating between countries.9 In our analyses we assess the associations of fundamental SDH known to be relevant to adolescent health with important adolescent-health outcomes including mortalitysexual healthhealth behavioursand mental health (we describe our methods in the appendix).
