Introduction

In recent years, mental health has been identified as a key public health concern, particularly for children and adolescents.1 2 According to WHO,3 mental health conditions account for 16% of the global burden of disease and injury for adolescents aged 10–19 years, with depression being identified as the leading cause of disability and illness among this population. Evidence suggests that half of all lifetime mental disorders will start during adolescence, yet the majority of these will go unrecognised and untreated.4 There are various factors which hinder the effective treatment of adolescent mental health. These include lack of resources, lack of communication between parents and healthcare practitioners, lack of policies aimed at child and adolescent health, and the ways in which mental health problems are diagnosed. According to Wissow et al,4 5 many children and adolescents have functional problems related to emotions or behaviour, but do not meet the criteria for diagnosis of a mental health disorder. It is critical though that such at-risk children and adolescents be identified so that appropriate prevention be put in place. This is concerning as adolescence represents a crucial period of development, where exposures, learnt behaviours and experiences can set the trajectory for an individual’s mental and physical health in adult life.3 4 The life course approach advocates for effective interventions during adolescence to protect public health investments in child survival and early childhood development, and to ensure the physical and mental health and development of the next generation.6 To this end, it is imperative to widen the focus from providing care and treatment for adolescents diagnosed with a mental health disorder to include those who are challenged with their mental health and well-being, before diagnoses is reached.

Studies exploring mental health problems among children and adolescents have found that there are various attitudinal, stigma related and structural barriers to accessing mental health services. Findings from a study suggested that 80% of children and adolescents who are in need of mental health services did not receive any.7 These barriers are particularly apparent among adolescents living with a chronic disorder or disease. According to WHO, the incidence and prevalence of chronic conditions is rising in most developed and low/middle-income countries (LMICs) and will constitute the main cause of death for children and adolescents by 2020.8 As such, it is necessary to consider mental health challenges in the context of adolescents living with chronic conditions.

Research has demonstrated that while children and adolescents with chronic health conditions are at increased risk for developing mental health problems, the overall mental well-being of chronically ill youth is largely determined by among others, the severity of the disease, the amount of treatment required and the psychological and social complications associated with such conditions.7 8 The variable nature of these factors have resulted in contradictory findings in different research studies. For example, studies have found gendered differences with chronically ill girls more likely to demonstrate emotional health problems than chronically ill boys when compared with healthy control groups.8

Findings from a South African study comparing psychological vulnerabilities among perinatally and behaviourally infected HIV positive adolescents found that perinatally infected adolescents were more likely to be adherent to antiretroviral therapy (ART) and retained in care while behaviourally infected adolescents were more likely to be depressed, report internalised stigma and express suicidal ideation.9 These findings suggests that adherence, retention in care and mental health problems among adolescents living with HIV (ALHIV) are differentially influenced by the mode of infection.9 As such, tailored interventions are recommended to address the differences between these groups to ensure optimal health outcomes. However, the differences between these two groups may also be influenced by external circumstances related to the care received rather than factors related to the disease. For example, perinatally infected adolescents receive support and build a trusting relationship with their healthcare worker while being in paediatric care.9 Behaviourally infected adolescents may not have the similar experiences in the healthcare system.

In the context of prioritising adolescent mental health, prevention and health promotion programmes have been identified as key strategies to help adolescents thrive.3 In line with the United Nations Sustainable Developmental Goal 3—which aims to promote well-being for all ages—many countries and organisations are aiming to improve the development of age appropriate interventions to provide psychosocial support and services to adolescents. For example, the Every Child Matters UK government initiative increased investment in child and adolescent mental health services to increase access to appropriate services.10 Additionally, global and local policies such as the Global Strategy for Women’s, Children’s and Adolescents’ Health,11 the Global Accelerated Action for the Health of Adolescents,12 the Lancet Commission on Adolescent Health and Well-being13 and the South African National Adolescent and Youth Policy 2017–202214, have identified adolescent mental health as a priority area and has committed to developing specific programmes to promote mental health among adolescents.

Despite the increased focus on adolescent mental health on the global health agenda, there is a lack of evidence concerning mental health conditions among adolescents, especially in LMICs (AHAH). According to Vreeman, McCoy and Lee,2 the lack of information about adolescent mental health in LMICs may be partially related to the lack of validated instruments for these contexts. To address this, UNICEF has launched a project to develop a measure of mental health among adolescents at the population level.3 This is of great significance as it will provide valuable evidence regarding the prevalence of mental disorders, inform policy-makers and healthcare workers, and guide intervention and treatment programmes. However, the aim of this instrument is majorly focused on improving data on the prevalence and burden of mental illness, meaning that adolescents who experience challenges to their mental health and well-being, but do not meet the characteristics for a mental diagnosis, may be overlooked.

It is argued that the development of valid instruments to measure mental health are dependent on the ways in which mental health is conceptualised. However, currently, there is little agreement on a general definition of ‘mental health’ which results in inconsistencies in the way mental health is being measured and addressed in global health policies.15 Traditionally, clinical psychologists focused more on the pathogenic side of mental health by describing and treating mental disorders. As such, mental health has popularly been used as a euphemism for ‘mental illness’.15 Consequently, the majority of the research focused on adolescent mental health adopts a pathological view by focusing on mental health disorders such as psychiatric disorders, general mental health disorders, emotional and behavioural problems, psychological distress and lower levels of illness symptoms as representative of mental well-being.2 16

However, this pathological view of mental health, and human health in general is not without its critiques. According to WHO, defining human health as more than the absence of illness has been ongoing and elusive objective.17 As Ryff18 argues, to advance our understanding of human health, we should also focus on the presence of wellness and what it means to flourish. In contrast to the pathological view of health, positive psychologists have focused on positive mental health or general mental15 health, which is defined not only as the absence of psychopathology, but also the presence of optimal well-being.19 From this point, mental health is viewed as including both hedonic (feeling well) and eudemonic (functioning well) traditions of well-being.

The concept of well-being in mental health has gained significant interest as evidence has shown that positive mental health functions as a recovery factor and a protective factor against both physical and mental illness.13 20 21 Studies have shown that high levels of well-being are associated with better health outcomes in both general and chronic adult populations, while low levels of well-being were associated with poorer health outcomes.20 For example, psychological factors, including well-being, has been associated with adjustment in patients diagnosed with hypertension.22 Additionally, research has shown that individuals who engage in diverse types of physical activity are more likely to report higher levels of psychological well-being than those who do not exercise, thereby suggesting a link between physical outcomes and well-being.23

There are fewer studies focused on adolescent health and psychological well-being. However, the available evidence shows that while adolescents may experience multiple physical, social and emotional changes which can negatively impact their mental well-being, providing psychosocial support and mental health promotion to support positive mental health can protect against psychopathology and support physical health.3 19 For example, a longitudinal study in Australia found that one-third of boys and nearly half of girls in a secondary school experienced an episode of depressive and anxiety symptoms. However, these episodes did not follow into their adult life thereby suggesting that interventions may prevent morbidity in later life.24 Additionally, research with ALHIV suggests that mental health well-being may play a role in supporting adherence to ART. A randomised control trial conducted by Willis et al25 found that adolescents who received the community adolescent treatment support intervention where 3.9 times more likely to be adherent to ART in comparison to those who only received standard of care.

While there may be disputes regarding the definition of mental health, there is agreement that mental health should be viewed as more than the absence of mental illness. To this end, WHO has adopted the complete state model to define mental health as ‘a state of wellness in which every individual realises his or her own potential, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community’.26 While this is a step forward in advancing our understanding of mental health in general, considerations should be made that focus specifically on adolescent mental health and its association with physical health, especially given the rise of chronic conditions. Understanding how positive mental health can be used as a resilience resource to protect against psychopathology and poor physical health outcomes is necessary to develop appropriate health policies and interventions. Measures aimed at diagnosing or screening mental health problems are useful in contexts where CAMHS are well developed and supported. However, LMICs like South Africa face challenges relating to lack of policy development and implementation for CAMHs, and a lack of resources and overburdened public healthcare facilities which challenges the sustainability of adolescent mental health and healthcare in general.27

Measurements of mental health play a significant role in policy and intervention development as these are used to provide empirical evidence regarding the effectiveness of programmes aimed at improving adolescent mental well-being. Focusing primarily on measuring low level symptoms of a disorder may result in ceiling effects by limiting the range of scores in a positive direction. Consequently, this limits the opportunity to measure the full range of mental health well-being.16 Additionally, based on evidence linking well-being and physical health outcomes, it is important to consider these associations in adolescence. Measuring mental health among adolescents necessitates the use of age appropriate and culturally valid instruments that can capture improvements in mental well-being where variances in general mental health can be accurately measured.16 28

More research focused on emphasising the healthy psychosocial development of adolescents that moves beyond identifying and addressing social and psychological problem trajectories is needed to support the development of psychosocial support programmes and interventions for adolescents who do not qualify for a mental illness diagnosis, yet experience challenges to their mental wellness.29 These interventions should be theory driven and accessible within the local culture without placing strain on healthcare systems, especially in resource limited contexts.24 30