Illness identity in adolescents with chronic illness: A long-term longitudinal inquiry into young adulthood

Up to 20% of Western adolescents have a chronic illness. Chronic illness has been described as a defining and transformational life experience, and many youth struggle with reconciling the illness with who they are as a person. A daunting challenge for research is to capture such ‘psychological individuality’, or the important psychological differences that distinguish one person from the other. One important framework that has garnered considerable attention holds a multi-layered, tripartite perspective on individuality, consisting of dispositional traits (the person as actor), identity commitment and exploration processes (the person as agent), and integrative life narratives (the person as author). Long-term research upholding such a differentiated and integrative perspective in individuals with a chronic illness is non-existent, despite the difficulties these youth may encounter in experiencing and constructing psychological individuality. The present overarching project extends two large longitudinal studies in adolescents and emerging adults with a chronic illness (type 1 diabetes and congenital heart disease) with three additional data-waves into young adulthood, generating two long-term studies (1) to examine and unpack psychological individuality in youth with a chronic illness from a developmental perspective; and (2) to investigate how the different layers of psychological individuality are related to long-term generic and illness-specific adaptation, social role functioning, and health care use. The present PhD will mainly focus on the second layer (the person as agent) and will examine how issues of identity and illness identity develop in the long-term in youth with chronic illnesses, and how these developments are related to long-term generic and illness-specific adaptation. Both variable-centered and person-centered analyses will be conducted, paying attention to both between-person and within-person effects.