Significant advances in health care have resulted in an overall decline in child mortality rates globally and more children are surviving to reach adolescence [1]. In 2016, adolescents (10–19 years) were estimated at 1.2 billion (18%) of the world population, making them the largest population of adolescents in history [1, 2]. Adolescents have been largely overlooked in global health and social policies, because this period is generally considered to be the healthiest in an individual’s life-course [1], and the unique health problems associated with adolescence have been misconstrued or ignored in favour of more pressing public health concerns [3]. However, changing health profiles of adolescents in both developed and developing countries have called attention to the diverse health needs of adolescents. According to the World Health Organization (WHO), more than 1.1 million adolescents died in 2016 - mostly from preventable or treatable causes [4]. Therefore, the considerable gains from global investments in child and maternal health programmes would yield fewer long term benefits without simultaneous investments in adolescent health [5, 6].
In this context, perspectives on adolescent health have shifted to recognise that adolescence represents a unique and formative developmental phase which is central in the development of capabilities related to health and wellbeing [6–8]. According to the life course approach, all stages of an individual’s life are intricately intertwined and interconnected with each other, as well as other people in society and with past and future generations of their families [9]. In other words, evidence has shown that early life experiences, including events experienced in pre-conception, play a role in determining the developmental origins and trajectories of health and wellbeing or disease across an individual’s life course [9]. From this perspective, it is understood that health and wellbeing of individuals, as well as communities, depend on interactions oscillating between multiple risk and protective factors throughout one’s life. Based on this, early and appropriate interventions during child and adolescent years are shown to be the most effective prevention strategies to promote optimal public health and human development [5, 6, 8]. Additionally, following the life course approach, it is argued that these early investments in child and adolescent health will yield a triple dividend as they will grow into healthier adults who can contribute positively to society, as well as the health and development of the next generation [9].
In response to changing adolescent health profiles, the prioritisation of adolescent health has become an increasingly prominent issue on global health agenda as seen in the Sustainable Developmental Goals (SDGs) [10], the Global Strategy for Women’s, Children’s and Adolescents’ Health [11], the Global Accelerated Action for the Health of Adolescents (AA-HA!) [3], the Lancet Commission on Adolescent Health and Well-being [1], and the South African National Department of Health’s National Adolescent and Youth Health Policy [12]. Furthermore, adolescents were included in the UNICEF’s Countdown to 2030 initiative, which previously focused on tracking child and maternal health in countries with the highest burden of child and maternal mortality [13]. However, the increased attention toward adolescent health has accentuated existing gaps as reports from the abovementioned initiatives have emphasised that there is a continued need for valid and reliable health data to drive accountability, identify priority areas and monitor progress in adolescent health [1, 3, 14]. To ensure a healthy and sustainable future for the world’s adolescents, special attention needs to be paid to understanding all aspects of adolescent health and development in context.
Globally, mental health issues constitute one of the greatest burdens of disease for adolescents. According to the WHO, in 2016 mental health conditions accounted for 16% of the global burden of disease and injury for adolescents, with depression being identified one of the leading causes of illness and disability among adolescents, suicide noted as the second leading cause of death in adolescents and self-harm the third [4, 15]. UNICEF propagates that half of all lifetime mental disorders have onset during adolescence [16]. The recent inclusion of adolescence on the global health agenda as a target group for intervention represents a key step toward reducing the global burden of disease attributed to mental health disorders and reducing preventable deaths. However, due to the previous neglect of mental health as a public health issue, efforts to address adolescent mental health are met with various challenges
Currently, there is a lack of data concerning mental health conditions among adolescents, especially those in low and –middle-income countries (LMICs) [17]. The lack of a body of quality evidence can affect the way adolescents are represented in national policies, as well as the ways in which government and healthcare officials respond to treatment and prevention. According to WHO, a 2014 review of health policy documents from 109 countries showed that 84% have given some attention to adolescents, with three-quarters of them addressing sexual and reproductive health; one-third addressing tobacco and alcohol use, and one-quarter focusing on mental health [2]. In LMICs, efforts regarding the promotion, prevention and treatment of child and adolescent mental health (CAMH) are hindered by a lack of specific CAMH policies, resources and have fewer child and adolescent psychiatrists and other mental health professionals [18, 19]. Furthermore, studies from developed countries have suggested that while CAMH services and policies are in place, there is a lack of mental health service uptake among children and adolescents due to various attitudinal, stigma-related, and structural barriers to accessing mental health services [20]. These challenges and barriers to CAMH in both LMICs and higher-income countries are particularly apparent among adolescents living with a chronic order or disease. Mental health conditions are increasingly recognised in children and adolescents with chronic conditions. Studies have shown that living with a chronic health condition is associated with increased risk of developing comorbid physical and mental health problems, which in turn influence treatment adherence and quality of life [21–23].
Another recurring obstacle for integrating mental health into global public health initiatives and frameworks is the lack of consensus of a definition of mental health [24]. Currently, the term ‘mental health’ is often used as a euphemism to refer to mental illness. This use reflects in the literature as the majority of adolescent mental health research adopts the dominant pathological view of health by focusing on mental health disorders such as psychiatric disorders, general mental health disorders, emotional and behavioural problems and psychological distress [17]. For example, Duffus et al. [21] observed that adolescents (aged 11–17 years) with type 1 diabetes presented with higher anxiety and depressive scores than their peers without a chronic disease. Research focused on exploring mental health among ALHIV have found similar results. A study conducted by Sherr et al. [25] found that that behaviourally infected ALHIV were more likely to be depressed, anxious and report internalised stigma than perinatally infected ALHIV, who were also found to be more adherent to antiretroviral therapy (ART). Similarly, global health initiatives such as AAH-HA! focus majorly on the burden of disease of mental disorders by reporting on self-harm, depressive disorders, childhood behavioural disorders and anxiety [3]. This dominant pathological view of mental health persists despite the contributions of positive health and well-being research [24]. In research and measurement, it is imperative to consider both mental health wellness and mental illness, as social scientists have argued that being free of mental illness does not constitute positive mental health [26]. Adolescents in particular experience multiple physical, social and emotional changes, which can positively or negatively impact their mental well-being. Therefore, interventions at this stage are crucial as research shows that providing psychosocial support and mental health promotion, such as psycho-education and community empowerment, facilitates the development of mental health wellness (positive mental health) which is protective against psychopathology (mental illness) [15, 26]. As such, mental health should be viewed as more than the absence of mental illness [27].
According to Vreeman, McCoy and Lee [17], the paucity of research on adolescent mental health and wellbeing may be related to the lack of validated instruments to measure mental health in all its facets. Therefore, it may be necessary to reconsider how mental health is conceptualised. WHO has adopted the complete state model to define mental health as ‘a state of wellness in which every individual realizes 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’ [28].
Despite the growth of wellbeing research in recent decades, the question of how wellbeing should be defined remains largely unresolved [29]. Consequently, this has given rise to broad and ambiguous definitions of wellbeing. The problem concerning the definition of wellbeing is not new, as Ryff argued early on that, there is a “particular neglect in the task of defining psychological wellbeing”[30]. As previously mentioned, there is a need to develop accurate and culturally appropriate measures of psychological wellbeing to support research endeavours that aim to improve adolescent mental health. Therefore, there is a greater necessity to clarify what is being measured, and how the resulting data from the measure should be interpreted to undertake fair and valid assessments. As such, developing a definition of mental health wellbeing should encompass more than the description of wellbeing itself (as is the case with current definitions) to a clear and definite statement of the exact meaning of the construct.
To this end, this integrative review aims to unpack the meaning of mental health wellness among adolescents and its associated constructs by analysing and synthesising peer-reviewed empirical and theoretical research on adolescent mental health. In doing this, we will develop a working definition of adolescent mental health wellness that can be used to develop an instrument aimed at measuring adolescent mental health wellness.