The present study was conducted to help understand the impact of living with multiple sclerosis (MS), an unpredictable, chronic illness that is widely known to have a large influence on psychosocial functioning, mental health, and life satisfaction (Motl & Gosney, 2007; Weiner, 2004). Recent research has begun to position certain chronic illnesses, such as MS, as traumatic events that influence mental health in both beneficial and detrimental ways. Thus, the present study investigated the positive and negative consequences of centralizing one’s identity within their MS experiences as related to trauma, growth, and psychosocial influences via a path model with 616 individuals with MS. The results indicate strong support for the hypothesized paths between the variables of interest—centrality of MS, posttraumatic stress, posttraumatic growth, social support, personal mastery, depression, and life satisfaction. Specifically, results indicate that posttraumatic stress and posttraumatic growth partially mediated the relations between centrality of MS with depression and life satisfaction. Moderation analyses indicated that social support and personal mastery did not moderate any relations between centrality of MS with depression and life satisfaction. Rather, additional analyses suggest social support and personal mastery may be viewed as additional mediators between centrality and posttraumatic stress and posttraumatic growth. The results of the present study is the first known study to extend trauma literature to the population of MS in order to provide an approach to help understand the high rates of depression and inconsistent findings on quality of life for this population. Implications for practice, theory and research are discussed.

This dissertation aims to elucidate the relationships between chronic illness, depression, and developmental assets among adolescents with chronic illness and co-morbid depression. Chapter One describes the current state of evidence on the intersections between chronic illness, depression, and adolescent development, and introduces Positive Youth Development theory and the Developmental Assets Framework. Chapter Two describes an integrative review synthesizing findings from 11 cohort studies examining relationships between depression or depressive symptoms and chronic illness-related disease control, self-management behaviors, illness-related morbidity, and quality of life among adolescents. Chapter Three describes a cross-sectional study comparing the number and types of developmental assets between adolescents with differing health statuses and examining relationships between assets and co-morbid depression using data from the 2016 National Survey of Children’s Health. Chapter Four describes a qualitative study exploring ways that developmental assets were discussed by 16 adolescents and young adults who lived with chronic illness and co-morbid depression during adolescence and uploaded videos to YouTube, a public video-sharing platform. Chapter Five summarizes key findings of this dissertation, outlines strengths and limitations, and discusses implications for future research, policy, and practice.