The World Health Organisation has defined the current era as one of epidemiological transition, where chronic medical issues are overtaking acute and even infectious disease as one of the most significant challenges facing health care providers internationally. Healthcare providers are struggling to provide the necessary medical resources needed to treat the growing population of people living with long-term health issues over a prolonged period of time – for example, in 2012, the Department of Health estimated that 70% of the annual healthcare in England spend could be attributed to those living with long-term conditions, and estimated that this figure would only rise in the coming decades. Highly implicit in these costs are the mental health issues which are disproportionately prevalent among this population. Co-morbid mental illness in the context of chronic physical illness has been established to lead to poorer physical health outcomes, decreased quality of life and increased healthcare expenditure. Therefore, interventions to reduce the burden of chronic illness in recent years have become increasingly focused on improving the well-being of people living with long-term medical issues.

Children and adolescents have been noticeably absent in the larger discourse on chronic illness and its related consequences. However, such an exclusion is severely curtailing our understanding of the course of chronic illness, especially when it comes to understanding the development of mental health issues among this population. In the general population, epidemiologists have been unable to establish whether it is chronic illness that causes the individual to become mentally distressed, or whether it is mental health issues, although they may not be diagnosed, that give rise to a number of behaviours which puts the individual at an increased risk for developing chronic illness. However, lifestyle factors cannot modify the development of chronic health conditions in younger populations, meaning that a disproportionate occurrence of mental health conditions would indicate some factor, specifically relating to living with chronic illness, that mediates the occurrence of mental health issues in this age group. Therefore, a specific focus on younger age groups could provide unique insight into critical factors mediating the relationship between chronic illness and mental health, in order to guide the provision of effective interventions both to this age group, and people living with long-term illness more generally. However, there are such significant limitations to the quality of the existing research focusing on mental health issues in chronically ill youths, that it cannot even be established that a disproportionate level of mental health issues truly exists among this population. This research project aims to address the limitations in previous research, in order to more thoroughly investigate the relationship between living with a chronic illness in childhood and adolescence and consequent psychological adjustment.